Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.DNA, Circular: Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Denaturation: Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Guanidine: A strong organic base existing primarily as guanidium ions at physiological pH. It is found in the urine as a normal product of protein metabolism. It is also used in laboratory research as a protein denaturant. (From Martindale, the Extra Pharmacopoeia, 30th ed and Merck Index, 12th ed) It is also used in the treatment of myasthenia and as a fluorescent probe in HPLC.Optical Rotatory Dispersion: The method of measuring the dispersion of an optically active molecule to determine the relative magnitude of right- or left-handed components and sometimes structural features of the molecule.Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Trifluoroethanol: A non-aqueous co-solvent that serves as tool to study protein folding. It is also used in various pharmaceutical, chemical and engineering applications.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Calorimetry, Differential Scanning: Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Kinetics: The rate dynamics in chemical or physical systems.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Polydeoxyribonucleotides: A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Anilino Naphthalenesulfonates: A class of organic compounds which contain an anilino (phenylamino) group linked to a salt or ester of naphthalenesulfonic acid. They are frequently used as fluorescent dyes and sulfhydryl reagents.Nucleic Acid Denaturation: Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Spectrophotometry, Infrared: Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Nuclear Magnetic Resonance, Biomolecular: NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.Molecular Conformation: The characteristic three-dimensional shape of a molecule.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Solutions: The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.G-Quadruplexes: Higher-order DNA and RNA structures formed from guanine-rich sequences. They are formed around a core of at least 2 stacked tetrads of hydrogen-bonded GUANINE bases. They can be formed from one two or four separate strands of DNA (or RNA) and can display a wide variety of topologies, which are a consequence of various combinations of strand direction, length, and sequence. (From Nucleic Acids Res. 2006;34(19):5402-15)Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Urea: A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.Protein Stability: The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Ultracentrifugation: Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Guanidines: A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.Calorimetry: The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Apoproteins: The protein components of a number of complexes, such as enzymes (APOENZYMES), ferritin (APOFERRITINS), or lipoproteins (APOLIPOPROTEINS).Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Protein Unfolding: Conformational transitions of the shape of a protein to various unfolded states.Micelles: Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.DNA, Z-Form: A left-handed double helix of DNA. Its name derives from its narrow zigzag structure that is the least twisted and thinnest form of DNA. Z-DNA forming regions within the GENOME may play an important role in GENE EXPRESSION REGULATION.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Ethidium: A trypanocidal agent and possible antiviral agent that is widely used in experimental cell biology and biochemistry. Ethidium has several experimentally useful properties including binding to nucleic acids, noncompetitive inhibition of nicotinic acetylcholine receptors, and fluorescence among others. It is most commonly used as the bromide.Protein Renaturation: The reconstitution of a protein's activity following denaturation.Spectrum Analysis, Raman: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.Synchrotrons: Devices for accelerating protons or electrons in closed orbits where the accelerating voltage and magnetic field strength varies (the accelerating voltage is held constant for electrons) in order to keep the orbit radius constant.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Magnetics: The study of MAGNETIC PHENOMENA.Bacterial Proteins: Proteins found in any species of bacterium.Drug Stability: The chemical and physical integrity of a pharmaceutical product.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Macromolecular Substances: Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Solvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)Protein Structure, Quaternary: The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).Intercalating Agents: Agents that are capable of inserting themselves between the successive bases in DNA, thus kinking, uncoiling or otherwise deforming it and therefore preventing its proper functioning. They are used in the study of DNA.Liposomes: Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Fluorescence: The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.Sodium Dodecyl Sulfate: An anionic surfactant, usually a mixture of sodium alkyl sulfates, mainly the lauryl; lowers surface tension of aqueous solutions; used as fat emulsifier, wetting agent, detergent in cosmetics, pharmaceuticals and toothpastes; also as research tool in protein biochemistry.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Titrimetry: The determination of the concentration of a given component in solution (the analyte) by addition of a liquid reagent of known strength (the titrant) until an equivalence point is reached (when the reactants are present in stoichiometric proportions). Often an indicator is added to make the equivalence point visible (e.g., a change in color).Polyribonucleotides: A group of 13 or more ribonucleotides in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.Lactoglobulins: Globulins of milk obtained from the WHEY.Lactalbumin: A major protein fraction of milk obtained from the WHEY.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Optical Rotation: The rotation of linearly polarized light as it passes through various media.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Molecular Weight: The sum of the weight of all the atoms in a molecule.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Protein Refolding: Conformational transitions of a protein from unfolded states to a more folded state.Oligonucleotides: Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Protein Multimerization: The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.Transition Temperature: The temperature at which a substance changes from one state or conformation of matter to another.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Biophysical Phenomena: The physical characteristics and processes of biological systems.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Dimyristoylphosphatidylcholine: A synthetic phospholipid used in liposomes and lipid bilayers for the study of biological membranes.X-Ray Diffraction: The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Melitten: Basic polypeptide from the venom of the honey bee (Apis mellifera). It contains 26 amino acids, has cytolytic properties, causes contracture of muscle, releases histamine, and disrupts surface tension, probably due to lysis of cell and mitochondrial membranes.Fluorescence Polarization: Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.Protein Engineering: Procedures by which protein structure and function are changed or created in vitro by altering existing or synthesizing new structural genes that direct the synthesis of proteins with sought-after properties. Such procedures may include the design of MOLECULAR MODELS of proteins using COMPUTER GRAPHICS or other molecular modeling techniques; site-specific mutagenesis (MUTAGENESIS, SITE-SPECIFIC) of existing genes; and DIRECTED MOLECULAR EVOLUTION techniques to create new genes.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.DNA, A-Form: An isoform of DNA that occurs in an environment rich in SODIUM and POTASSIUM ions. It is a right-handed helix with 11 base pairs per turn, a pitch of 0.256 nm per base pair and a helical diameter of 2.3 nm.Histidine: An essential amino acid that is required for the production of HISTAMINE.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Poly dA-dT: Polydeoxyribonucleotides made up of deoxyadenine nucleotides and thymine nucleotides. Present in DNA preparations isolated from crab species. Synthetic preparations have been used extensively in the study of DNA.Salts: Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Oligodeoxyribonucleotides: A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Solubility: The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Amyloid: A fibrous protein complex that consists of proteins folded into a specific cross beta-pleated sheet structure. This fibrillar structure has been found as an alternative folding pattern for a variety of functional proteins. Deposits of amyloid in the form of AMYLOID PLAQUES are associated with a variety of degenerative diseases. The amyloid structure has also been found in a number of functional proteins that are unrelated to disease.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Trypsin: A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Horses: Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.Zinc: A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.Surface Plasmon Resonance: A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.Muramidase: A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Microscopy, Atomic Force: A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.Serum Albumin: A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.Chymotrypsin: A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Bromosuccinimide: A brominating agent that replaces hydrogen atoms in benzylic or allylic positions. It is used in the oxidation of secondary alcohols to ketones and in controlled low-energy brominations. (From Miall's Dictionary of Chemistry, 5th ed; Hawley's Condensed Chemical Dictionary, 12th ed,).Phosphatidylglycerols: A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.Phosphatidylcholines: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Porphyrins: A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.Erabutoxins: Toxins isolated from the venom of Laticauda semifasciata, a sea snake (Hydrophid); immunogenic, basic polypeptides of 62 amino acids, folded by four disulfide bonds, block neuromuscular end-plates irreversibly, thus causing paralysis and severe muscle damage; they are similar to Elapid neurotoxins.Gramicidin: A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN.Cobalt: A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Detergents: Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.Poly G: A group of guanine ribonucleotides in which the phosphate residues of each guanine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.Mutant Proteins: Proteins produced from GENES that have acquired MUTATIONS.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Energy Transfer: The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.Ferrous Compounds: Inorganic or organic compounds that contain divalent iron.Antimicrobial Cationic Peptides: Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins. They displace DIVALENT CATIONS from phosphate groups of MEMBRANE LIPIDS leading to disruption of the membrane.Static Electricity: The accumulation of an electric charge on a objectSilica Gel: A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for CHROMATOGRAPHY. The fully hydrated form of silica gel has distinct properties and is referred to as SILICIC ACID.Models, Structural: A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)Metalloproteins: Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Unilamellar Liposomes: Single membrane vesicles, generally made of PHOSPHOLIPIDS.Congo Red: An acid dye used in testing for hydrochloric acid in gastric contents. It is also used histologically to test for AMYLOIDOSIS.Copper: A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.Oligopeptides: Peptides composed of between two and twelve amino acids.Bacteriochlorophylls: Pyrrole containing pigments found in photosynthetic bacteria.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Alanine: A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.Micrococcal Nuclease: An enzyme that catalyzes the endonucleolytic cleavage to 3'-phosphomononucleotide and 3'-phospholigonucleotide end-products. It can cause hydrolysis of double- or single-stranded DNA or RNA. (From Enzyme Nomenclature, 1992) EC 3.1.31.1.Membranes, Artificial: Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.Lysine: An essential amino acid. It is often added to animal feed.Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Acrylamide: A colorless, odorless, highly water soluble vinyl monomer formed from the hydration of acrylonitrile. It is primarily used in research laboratories for electrophoresis, chromatography, and electron microscopy and in the sewage and wastewater treatment industries.Buffers: A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.Biopolymers: Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.Bisbenzimidazole: A benzimidazole antifilarial agent; it is fluorescent when it binds to certain nucleotides in DNA, thus providing a tool for the study of DNA replication; it also interferes with mitosis.Netropsin: A basic polypeptide isolated from Streptomyces netropsis. It is cytotoxic and its strong, specific binding to A-T areas of DNA is useful to genetics research.Deoxyribonucleoproteins: Proteins conjugated with deoxyribonucleic acids (DNA) or specific DNA.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Amphibian Proteins: Proteins obtained from species in the class of AMPHIBIANS.

R73A and H144Q mutants of the yeast mitochondrial cyclophilin Cpr3 exhibit a low prolyl isomerase activity in both peptide and protein-folding assays. (1/11120)

Previously we reported that the R73A and H144Q variants of the yeast cyclophilin Cpr3 were virtually inactive in a protease-coupled peptide assay, but retained activity as catalysts of a proline-limited protein folding reaction [Scholz, C. et al. (1997) FEBS Lett. 414, 69-73]. A reinvestigation revealed that in fact these two mutations strongly decrease the prolyl isomerase activity of Cpr3 in both the peptide and the protein-folding assay. The high folding activities found previously originated from a contamination of the recombinant Cpr3 proteins with the Escherichia coli protein SlyD, a prolyl isomerase that co-purifies with His-tagged proteins. SlyD is inactive in the peptide assay, but highly active in the protein-folding assay.  (+info)

Biophysical characterization of the structure of the amino-terminal region of gp41 of HIV-1. Implications on viral fusion mechanism. (2/11120)

A peptide of 51 amino acids corresponding to the NH2-terminal region (5-55) of the glycoprotein gp41 of human immunodeficiency virus type 1 was synthesized to study its conformation and assembly. Nuclear magnetic resonance experiments indicated the sequence NH2-terminal to the leucine zipper-like domain of gp41 was induced into helix in the micellar solution, in agreement with circular dichroism data. Light scattering experiment showed that the peptide molecules self-assembled in water into trimeric structure on average. That the peptide molecules oligomerize in aqueous solution was supported by gel filtration and diffusion coefficient experiments. Molecular dynamics simulation based on the NMR data revealed a flexible region adjacent to the hydrophobic NH2 terminus of gp41. The biological significance of the present findings on the conformational flexibility and the propensity of oligomerization of the peptide may be envisioned by a proposed model for the interaction of gp41 with membranes during fusion process.  (+info)

Reaction specificity of native and nicked 3,4-dihydroxyphenylalanine decarboxylase. (3/11120)

3,4-Dihydroxyphenylalanine (Dopa) decarboxylase is a stereospecific pyridoxal 5'-phosphate (PLP)-dependent alpha-decarboxylase that converts L-aromatic amino acids into their corresponding amines. We now report that reaction of the enzyme with D-5-hydroxytryptophan or D-Dopa results in a time-dependent inactivation and conversion of the PLP coenzyme to pyridoxamine 5'-phosphate and PLP-D-amino acid Pictet-Spengler adducts, which have been identified by high performance liquid chromatography. We also show that the reaction specificity of Dopa decarboxylase toward aromatic amines depends on the experimental conditions. Whereas oxidative deamination occurs under aerobic conditions (Bertoldi, M., Moore, P. S., Maras, B., Dominici, P., and Borri Voltattorni, C. (1996) J. Biol. Chem. 271, 23954-23959; Bertoldi, M., Dominici, P., Moore, P. S., Maras, B., and Borri Voltattorni, C. (1998) Biochemistry 37, 6552-6561), half-transamination and Pictet-Spengler reactions take place under anaerobic conditions. Moreover, we examined the reaction specificity of nicked Dopa decarboxylase, obtained by selective tryptic cleavage of the native enzyme between Lys334 and His335. Although this enzymatic species does not exhibit either decarboxylase or oxidative deamination activities, it retains a large percentage of the native transaminase activity toward D-aromatic amino acids and displays a slow transaminase activity toward aromatic amines. These transamination reactions occur concomitantly with the formation of cyclic coenzyme-substrate adducts. Together with additional data, we thus suggest that native Dopa decarboxylase can exist as an equilibrium among "open," "half-open," and "closed" forms.  (+info)

SNARE interactions are not selective. Implications for membrane fusion specificity. (4/11120)

The SNARE hypothesis proposes that membrane trafficking specificity is mediated by preferential high affinity interactions between particular v (vesicle membrane)- and t (target membrane)-SNARE combinations. The specificity of interactions among a diverse set of SNAREs, however, is unknown. We have tested the SNARE hypothesis by analyzing potential SNARE complexes between five proteins of the vesicle-associated membrane protein (VAMP) family, three members of the synaptosome-associated protein-25 (SNAP-25) family and three members of the syntaxin family. All of the 21 combinations of SNAREs tested formed stable complexes. Sixteen were resistant to SDS denaturation, and most complexes thermally denatured between 70 and 90 degreesC. These results suggest that the specificity of membrane fusion is not encoded by the interactions between SNAREs.  (+info)

The putative bioactive surface of insect-selective scorpion excitatory neurotoxins. (5/11120)

Scorpion neurotoxins of the excitatory group show total specificity for insects and serve as invaluable probes for insect sodium channels. However, despite their significance and potential for application in insect-pest control, the structural basis for their bioactivity is still unknown. We isolated, characterized, and expressed an atypically long excitatory toxin, Bj-xtrIT, whose bioactive features resembled those of classical excitatory toxins, despite only 49% sequence identity. With the objective of clarifying the toxic site of this unique pharmacological group, Bj-xtrIT was employed in a genetic approach using point mutagenesis and biological and structural assays of the mutant products. A primary target for modification was the structurally unique C-terminal region. Sequential deletions of C-terminal residues suggested an inevitable significance of Ile73 and Ile74 for toxicity. Based on the bioactive role of the C-terminal region and a comparison of Bj-xtrIT with a Bj-xtrIT-based model of a classical excitatory toxin, AaHIT, a conserved surface comprising the C terminus is suggested to form the site of recognition with the sodium channel receptor.  (+info)

Properties of non-polymerizable tropomyosin obtained by carboxypeptidase A digestion. (6/11120)

Tropomyosin digested with carboxypeptidase A [EC 3.4.12.2] (CTM) shows a lower viscosity than the undigested protein in solution. From the relation between the viscosity decrease and the amount of amino acids liberated from the carboxyl terminus during this digestion, it is inferred that loss of the tri-peptide-Thr-Ser-Ile from the C-terminus is responsible for the decrease in viscosity. The secondary structure of -TM was not affected by the digestion according to circular dichroic measurements. The viscosity of CTM did not increase in methanol-water mixtures, whereas that of tropomyosin increased markedly. These results indicate that polymerizability was lost upon the removal of a small peptide from the C-terminus without change in the secondary structure. A decrease in the viscosity of tropomyosin solutions was observed on the addition of CTM, indicating that CTM interacts with intact tropomyosin. The dependence of the viscosity decrease on the amount of CTM showed that CTM binds tropomyosin in a one-to-one ratio as a result of end-to-end interaction. Since paracrystals having a 400 A repeated band structure could be grown in the presence of Mg ions at neutral pH, side-by-side interactions in CTM molecules remain intact, even though polymerizability is lost. The disc gel electrophoretic pattern showed that troponin could bind to CTM, but no increase in viscosity due to the complex was observed in solution. That is, the C-terminal part of tropomyosin is not required for the formation of the complex. The amount of CTM bound to F-actin was less than half of that bound to undigested tropomyosin, and could be reduced to one-tenth by a washing procedure. In the presence of troponin, however, the amount recovered to the level of tropomyosin normally bound to F-actin. Therefore, it is concluded that troponin is bound in the middle of the tropomyosin molecule and strengthens the binding of tropomyosin to F-actin.  (+info)

Characterisation of copper-binding to the second sub-domain of the Menkes protein ATPase (MNKr2). (7/11120)

The Menkes ATPase (MNK) has an essential role in the translocation of copper across cellular membranes. In a complementary manner, the intracellular concentration of copper regulates the activity and cellular location of the ATPase through its six homologous amino-terminal domains. The roles of the six amino-terminal domains in the activation and cellular trafficking processes are unknown. Understanding the role of these domains relies on the development of an understanding of their metal-binding properties and structural properties. The second conserved sub-domain of MNK was over-expressed, purified and its copper-binding properties characterised. Reconstitution studies demonstrate that copper binds to MNKr2 as Cu(I) with a stoichiometry of one copper per domain. This is the first direct evidence of copper-binding to the MNK amino-terminal repeats. Circular dichroism studies suggest that the binding or loss of copper to MNKr2 does not cause substantial changes to the secondary structure of the protein.  (+info)

Biophysical characterization of a designed TMV coat protein mutant, R46G, that elicits a moderate hypersensitivity response in Nicotiana sylvestris. (8/11120)

The hypersensitivity resistance response directed by the N' gene in Nicotiana sylvestris is elicited by the tobacco mosaic virus (TMV) coat protein R46G, but not by the U1 wild-type TMV coat protein. In this study, the structural and hydrodynamic properties of R46G and wild-type coat proteins were compared for variations that may explain N' gene elicitation. Circular dichroism spectroscopy reveals no significant secondary or tertiary structural differences between the elicitor and nonelicitor coat proteins. Analytical ultracentrifugation studies, however, do show different concentration dependencies of the weight average sedimentation coefficients at 4 degrees C. Viral reconstitution kinetics at 20 degrees C were used to determine viral assembly rates and as an initial assay of the rate of 20S formation, the obligate species for viral reconstitution. These kinetic results reveal a decreased lag time for reconstitution performed with R46G that initially lack the 20S aggregate. However, experiments performed with 20S initially present reveal no detectable differences indicating that the mechanism of viral assembly is similar for the two coat protein species. Therefore, an increased rate of 20S formation from R46G subunits may explain the differences in the viral reconstitution lag times. The inferred increase in the rate of 20S formation is verified by direct measurement of the 20S boundary as a function of time at 20 degrees C using velocity sedimentation analysis. These results are consistent with the interpretation that there may be an altered size distribution and/or lifetime of the small coat protein aggregates in elicitors that allows N. sylvestris to recognize the invading virus.  (+info)

Research Corridor has published a new research study titled "Circular Dichroism Spectroscopy Market - Growth, Share, Opportunities, Competitive Analysis and Forecast, 2017 - 2025". The Circular Dichroism Spectroscopy Market report studies current as well as future aspects of the Circular Dichroism Spectroscopy Market based upon factors such as market dynamics, key ongoing trends and segmentation analysis. Apart from the above elements, the Circular Dichroism Spectroscopy Market research report provides a 360-degree view of the Lipstick Packing industry with geographic segmentation, statistical forecast and the competitive landscape.. Browse the complete report at http://www.researchcorridor.com/circular-dichroism-spectroscopy-market/. Geographically, the Circular Dichroism Spectroscopy Market report comprises dedicated sections centering on the regional market revenue and trends. The Circular Dichroism Spectroscopy Market has been segmented on the basis of geographic regions into North America, ...
The relative configuration of a key subunit of hemicalide, a recently isolated, highly bioactive marine natural product having potent antiproliferative activity against a panel of human cancer cell lines, was assigned by combining stereocontrolled synthesis of model substrates with NMR, IR, and vibrational circular dichroism (VCD) spectroscopy. The assignment of the absolute configuration of asymmetric carbon center C42 in two structurally complex epimeric substructures containing six stereocenters by VCD analysis illustrates the power and reliability of combining methods. ...
Nicu, V. and Neugebauer, J. and Wolff, S. and Baerends, E. 2008. A vibrational circular dichroism implementation within a Slater-type-orbital based density functional framework and its application to hexa- and hepta-helicenes. Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 119: pp. 245-263 ...
Circular dichroism measurements of ArsTM (purple) and MamAΔ41 proteins from RS-1 (Blue) Mbav (orange), AMB-1 (green) and MSR-1 (red).(A) Circular dichroism spe
Bertucci C., Cimitan S., Riva A., Morazzoni P.. The binding to human serum albumin (HSA) of the antitumoural drug paclitaxel and of several structural analogues has been characterized by bioaffinity chromatography and circular dichroism. A ranking of the taxanes was obtained for their affinity to the protein by measuring their retention times on an albumin chromatographic column. This also allowed the calculation of the drug bound percentage. Affinity resulted significantly affected by the nature of the isoserinic side chain, the presence of the 1,14-carbonate moiety and the substituent at C-7, showing that the hydrophobicity of the drug is fundamental in the binding process. The analysis demonstrated that the organic solvent highly alters the interaction mechanism of taxanes to the protein and so the affinity results. Circular dichroism experiments supported this hypothesis. Furthermore, taxanes binding to the serum carrier was characterized by displacement chromatography, by adding into the ...
The preparations of pentaamminecobalt(III) complexes of a series of asymmetric unidentate amines are reported. The circular dichroism spectra for the (S)-amines show negative Cotton effects under the A → T absorption band, which are somewhat solvent dependent but independent of temperature down to -190°C. The vicinal effect from 1-cyclohexylethylamine was comparable to that from analogous aromatic compounds, but the simpler alkyl derivatives were found to impose smaller rotational strengths on the d-d transitions. The lack of measurable c.d. in the visible region for tetraammine((S)-butane-1, 3-diamine)cobalt(III) is reported and discussed in the light of the other studies ...
Read "Secondary Structure of Proteins Through Circular Dichroism Spectroscopy, Annual Review of Biophysics" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Philip J. Stephens was a theoretical chemist who brought to fruition two new forms of optical spectroscopy, using circularly polarized light, for the determination of electronic structure and molecular stereochemistry. The first was magnetic circular dichroism (MCD), the wavelength dependence of the differential absorption of left and right circularly polarized light induced by a magnetic field applied parallel to the light beam. Stephens established a methodology for extracting from MCD spectra the angular momentum characteristics of ground and excited electronic states and demonstrated applications to the assignment of the optical spectra of coordination complexes of transition metals and to metalloproteins. In the second half of his career Stephens led the field of vibrational circular dichroism (VCD), the measurement of the natural circular dichroism (CD) arising from the vibrational transitions of chiral molecules. He developed instrumental techniques to measure this weak dichroism over a ...
Circular Dichroism (CD) analysis from SGS - meet regulatory requirements with class-leading CD spectroscopic analysis, alpha helix beta sheet analysis, and secondary and tertiary structure analysis. Learn more.
The circular-dichroism and proton-magnetic-resonance spectra of complexes of ribonuclease A with dihydrouridine 3′-phosphate, 2′- and 3′-CMP, arabinosyl-3′-CMP, 1-(2-hydroxyethyl)cytosine 2′-phosphate and 1-(3-hydroxypropyl)cytosine 3′-phosphate were studied. Comparison of the results shows that non-additivity of the circular-dichroic spectrum of an enzyme-nucleotide complex may be due to: (a), alteration of the circular dichroic spectrum of the nucleotide under the influence of the asymmetric protein matrix (induced dichroism), and (b) a change in the nucleotide conformation. The contribution of each of the two factors was estimated to calculate the circular-dichoroic spectra of 2′-CMP and 3′-CMP in complex with ribonuclease A. 3′-CMP in this complex was characterized by negative circular dichroism in the long-wavelength absorption band of the nucleotide, whereas 2′-CMP was characterized by positive circular dichroism. Since both nucleotides in the complex are known to be in ...
Circular dichroism (CD) spectroscopy is an optical technique that measures the difference in the absorption of left and right circularly polarized light. This technique has been widely employed in the studies of nucleic acids structures and the use of it to monitor conformational polymorphism of DNA has grown tremendously in the past few decades. DNA may undergo conformational changes to B-form, A-form, Z-form, quadruplexes, triplexes and other structures as a result of the binding process to different compounds. Here we review the recent CD spectroscopic studies of the induction of DNA conformational changes by different ligands, which includes metal derivative complex of aureolic family drugs, actinomycin D, neomycin, cisplatin, and polyamine. It is clear that CD spectroscopy is extremely sensitive and relatively inexpensive, as compared with other techniques. These studies show that CD spectroscopy is a powerful technique to monitor DNA conformational changes resulting from drug binding and also
A new method to detect the vibrational CD (VCD) of a localized part of a chiral mol. system is reported. A local VCD amplifier was implemented, and the distance dependence of the amplification was investigated in a series of peptides. The results indicate a characteristic distance of 2.0±0.3 bonds, which suggests that the amplification is a localized phenomenon. The amplifier can be covalently coupled to a specific part of a mol., and can be switched ON and OFF electrochem. By subtracting the VCD spectra obtained when the amplifier is in the ON and OFF states, the VCD of the local environment of the amplifier can be sepd. from the total VCD spectrum. Switchable local VCD amplification thus makes it possible to "zoom in" on a specific part of a chiral mol ...
A series of polypeptides with well-defined sequences, (Asp3Phe1)n, (Asp2Phe1)n, (Asp1Phe1)n, (Asp1Phe2)n, and (Asp1Phe3)n, containing the hydrophilic amino acid, aspartic acid (Asp) and the hydrophobic amino acid, phenylalanine (Phe), were synthesized. Their behaviour in aqueous solution was investigated by performing fluorescence quenching and non-radiative energy transfer (NRET) experiments which were complemented by dynamic (DLS) and static (SLS) light scattering. The photophysical properties of the polypeptides were dependent on their Phe content. An increase in the Phe content led to an increase in the extinction coefficient, fluorescence quantum yield, and fluorescence average lifetime of the polypeptides. Circular dichroism experiments revealed that except for the (Asp1Phe3)n polypeptide, which adopts an alpha-helical conformation in aqueous solution, the other polypeptides did not adopt any known conformation in solution. The fluorescence quenching studies performed using molecular ...
Circular dichroism (CD) is a powerful technique for studying the structures of proteins in solution, as well as structural changes that may occur when proteins bind to ligands
The Aviv Circular Dichroism Spectrometer, model 215, records CD as a function of wavelength, time, temperature, pH and concentration using a double monochromator containing two UV grade prisms as dispersing elements. Right and left circularly polarized light is produced by a 50 KHz photoelastic modulator.. The instrument includes software by AVIV for instrument control, data acquisition and processing in a Windows environment.. ...
Ferromagnetic amorphous oxides in the EuO-TiO[2] system studied by the Faraday effect in the visible region and the x-ray magnetic circular dichroism at the Eu M[4,5] and L[2,3] edges (2013 ...
The extension of circular dichroism measurements into the VUV region was motivated by the need to provide supplementary techniques to the absorption studies lacking rotational and vibrational structure. CD as one of these techniques is determined by selection rules which differ from those in absorption and thus enables the assignment of excited electronic states. Another application of VUVCD measurements is the use of correlation between the sign of the CD signal and the absolute configuration to formulate sector rules of chromophores absorbing only in the VUV. In this review we will present results obtained on our home-made instrument capable of measuring CD signal down to 150 nm. These applications of VUVCD will be demonstrated in systems such as the oxirane chromophore, the methylenecyclohexene chromophore and the amine chromophore. The role of singlet-triplet transitions and their contribution to CD and ORD will also be discussed. ...
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
In this report, we provide an x-ray magnetic circular dichroism (XMCD) study for 100?nm thick epitaxial magnetite (Fe3O4) films on MgO (001) and Al2O3 (0001) substrates. For XMCD, we recorded the surface sensitive total electron yield and the bulk sensitive transmission spectra. From the analysis of the XMCD data, we find an increased Fe spin moment (10% larger) at the surface of the film on MgO (100) with respect to the corresponding bulk value of the film. Surface and bulk spin moments of the film on Al2O3(0001) are almost equal. For both films, the bulk orbital to spin moments ratio increases from zero at 70?K to 0.03?0.04 at 300?K. For Fe3O4/MgO (001), the surface orbital to spin moment ratio behaves similarly to the bulk value, while the orbital to spin moments ratio is increased at the Fe3O4/Al2O3 (0001) surface to 0.06. The observed differences between films grown on MgO and Al2O3 are explained within the framework of differences in mismatch strain experienced by the films. ...
Biophotonics. Bioelectromagnetics. Calcium imaging. Calorimetry. Chromatography. Circular dichroism. Computational chemistry. Cryobiology. Dual-polarization. .
The CD spectra of d(GGGGTTTTGGGG) and d(TGGGGTTGGGGT) in the presence of 5 and 140 mM sodium are shown in the upper panels. The CD spectra of these DNAs in the
Circular Dichroism, DNA, Absorption, Nickel, Z-dna, B-dna, Report, Spermine, Cadmium, Concentrations, Cytosine, Guanine, Fluorescence, Ionic Strength, Oligonucleotides, Adenine, Electronic, Light, Porphyrins, Sensitivity
Kinase, Lipids, Membrane, Liposomes, Membranes, Micelles, Rapamycin, Association, Circular Dichroism, Concentrations, Environment, Fkbp12, Growth, Magnetic, Magnetic Resonance, Membrane Protein, Metabolism, Neurological Disorders, Nuclear Magnetic Resonance, Phosphatidic Acid
The Dark Animus 10hc topic was quite useful so I figured perhaps people have some advice for lei shen 10hc. Currently getting to the second transition, getting past the first transition without casualties is our current main issue so we waste alot of attempts on that. Any input overall is welcome tho.
The purpose of Circular 2010/4 is to provide APS agencies with updated information originally published in Circular 2006/1 about the: Special Measures provision for recruiting Indigenous staff; and Identified Positions/Criteria provision for recruiting staff with specialist knowledge and understanding for roles with a strong involvement in work relating to Indigenous
Shop Circular Saws at acehardware.com and get Free Store Pickup at your neighborhood Ace. Buy Online & Pickup Today. See Details.
This example covers four tests that are available in the StatsCircularTwoSampleTest operation. All tests are used to compare two samples of circular data which represent either raw data or means of data (second order analysis).. For the first two examples we use the waves Sample1, Sample2 and Sample3:. ...
Hi everyone, I create a blank solution, then create two class projects in it. Its a requirement that i must create a reference from each project to the other. But VS doesnt allow me to do it. It...
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245 ...
push complete. go ahead and test it out :) Updating code... Updating vendor submodules... syncdb migrate manage.py tasks... Cleaning gitignore and pyc files... Storing revision information... finished at Mon Apr 30 14:13:33 PDT 2012 Deploying code... [2012-04-30 14:13:33] Running rsync_project [2012-04-30 14:13:33] [localhost] running: /usr/bin/rsync -aq --include .gitkeep --exclude .git* --exclude .hg* --delete /data/genericrhel6-stage/src/mozillalabs.allizom.org/ /data/genericrhel6-stage/www/mozillalabs.allizom.org/ [2012-04-30 14:13:35] [localhost] finished: /usr/bin/rsync -aq --include .gitkeep --exclude .git* --exclude .hg* --delete /data/genericrhel6-stage/src/mozillalabs.allizom.org/ /data/genericrhel6-stage/www/mozillalabs.allizom.org/ (2.497s) [2012-04-30 14:13:35] Running commit_www [2012-04-30 14:13:35] [localhost] running: cd /data/genericrhel6-stage/www && /usr/bin/git add .; /usr/bin/git commit -a -m deploy [2012-04-30 14:14:09] [localhost] finished: cd ...
article{9c427bbf-e48d-404f-aa8d-386a5072b5fd, abstract = {,p,Apolipoprotein A-I (apoA-I) in high-density lipoprotein (HDL) provides cardiovascular protection. Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to analyze the dynamic solution structure of the apoA-I protein in the apo- and HDL-states and the protein structure conversion in HDL formation. Wild-type apoA-I protein was compared to human variants that either are protective (R173C, Milano) or lead to increased risk for ischaemic heart disease (A164S). Comparable secondary structure distributions in the HDL particles, including significant levels of beta strand/turn, were observed. ApoA-I Milano in HDL displayed larger size heterogeneity, increased protein flexibility, and an altered lipid-binding profile, whereas the apoA-I A164S in HDL showed decrease thermal stability, potentially linking the intrinsic HDL propensities of the variants to disease risk.,/p,}, articleno = {13540}, author = {Giudice, Rita Del and ...
New advances in instrumentation, demonstration of proof-of-principle studies, and development of new tools and methods for data analysis and interpretation have enabled the technique of Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy to become a useful tool for structural and functional biology. This paper discusses the characterisation of two new SRCD beamlines, CD1 at the Institute for Storage Rings (ISA), Denmark and 4B8 at the Beijing Synchrotron Radiation Facility (BSRF), China, and new applications of the method for examining biological systems ...
We present here a study of the magnetic properties of the Nd2−xHoxFe14B series. The macroscopic properties of these compounds evolve continuously from those of Nd2Fe14B to those of Ho2Fe14B as Ho gradually replaces Nd. The system shows a compensation of the rare-earth sublattice magnetization for a critical concentration, xc=0.55, that is reflected into the anomalous behavior of both macroscopic and microscopic magnetic probes. The combined analysis of magnetization, 57Fe Mössbauer spectroscopy and Fe K-edge x-ray magnetic circular dichroism (XMCD) measurements suggests that the origin of the anomalous magnetic behavior found at xc=0.55 is mainly due to the Ho sublattice. Moreover, the analysis of the Fe K-edge XMCD signals reveal the presence of a rare-earth contribution, reflecting the coupling of the rare-earth and Fe magnetic moments, which can lead to the possibility of disentangling the magnetic behavior of both Fe and R atoms using a single absorption edge ...
The Protein Circular Dichroism Data Bank (PCDDB) is a web-based resource containing circular dichroism (CD) and synchrotron radiation circular dichroism spectral and associated metadata located at http://pcddb.cryst.bbk.ac.uk. This resource provides a freely available, user-friendly means of accessing validated CD spectra and their associated experimental details and metadata, thereby enabling broad usage of this material and new developments across the structural biology, chemistry, and bioinformatics communities. The resource also enables researchers utilizing CD as an experimental technique to have a means of storing their data at a secure site from which it is easily retrievable, thereby making their results publicly accessible, a current requirement of many grant-funding agencies world-wide, as well as meeting the data-sharing requirements for journal publications. This tutorial provides extensive information on searching, accessing, and downloading procedures for those who wish to utilize ...
MILLS, M.; LIN, C.; CHAUHAN, M. and KLUMP, H.H.. Circular dichroism as a means to follow DNA gymnastics: on the shoulders of giants. S. Afr. j. sci. [online]. 2009, vol.105, n.7-8, pp.309-311. ISSN 1996-7489.. This is the first report of DNA stem-loops self-assembled by foot-loop interactions into either two-dimensional strings or three-dimensional spirals, distinguished by circular dichroism spectroscopy. All subunits are linked by cooperative Watson-Crick hydrogen bonds.. Keywords : DNA; circular dichroism; nanostructures; stem-loop structures; self-assembly. ...
Angewandte Chemie DOI: 10.1002/ange.201006255 H2 Activation Iron-Chromophore Circular Dichroism of [Fe]-Hydrogenase: The Conformational Change Required for H2 Activation** Seigo Shima,* Sonja Vogt, Andreas Gbels, and Eckhard Bill Circular dichroism (CD) spectroscopy is a very sensitive method used to detect changes in inherently chiral chromophores and in achiral chromophores embedded in chiral surroundings.[1] Information on the secondary structures of proteins can be obtained by CD spectroscopy in the far-UV spectral region (190-250 nm), and CD in the near-UV region (250-350 nm) can be sensitive to certain aspects of tertiary structure.[1b] Near-UV and visible CD spectroscopy is also used to analyze metal complexes[1a,c] and the active site of metal-containing enzymes, such as P450 (300-500 nm), galactose oxidase (300-700 nm), and biotin sulfoxide reductase (300-650 nm).[2] The [Fe]-hydrogenase found in many methanogenic archaea catalyzes the reversible reduction of ...
We compared various spectroscopic properties of a norfloxacin-single stranded DNA complex with those of norfloxacin-double stranded DNA complex. Norfloxacin binds to both double- and single stranded DNA, and we observed the following spectroscopic changes for both complexes: hypochromism in the norfloxacin absorption region in the absorption spectrum, the characteristic induced CD spectrum consisting of a weak positive band at 323 nm and a strong positive band at 280-300 nm followed by a negative band in the 260 nm region, a strong decrease in the fluorescence intensity and a red-shift in the fluorescence emission spectrum, and shorter fluorescence decay times. These results indicate that the environments of the bound norfloxacin in both DNAs are similar, although the equilibrium constant of the norfloxacin-single stranded DNA was twice as high as the norfloxacin-double stranded DNA complex. Both complexes were thermodynamically favored with similar negative ΔGo. Negative ΔHo terms contribute ...
Ligand binding properties of five single amino acid substituted variants (V11A, D12A, Q15A, Q15E, and F16A) of human insulin-like growth factor I (IGF-I) were analyzed with respect to their binding affinities and binding kinetics to recombinant IGF binding protein 1 (IGFBP-1) and a soluble form of the IGF type I receptor (sIGF-I(R)), respectively. Side chains of the substituted residues are all predicted to be the most surface exposed in the alpha-helical portion of the B-region of the IGF-I molecule. The IGF-I variants were produced as fusion proteins to a IgG(Fc) binding protein domain, Z. Ligand binding kinetic rates were determined using BIAcore biosensor interaction analysis technology. All IGF-I variants showed altered binding affinities to both IGFBP- I and sIGF-I(R). Secondary structure content of the IGF-I variants was estimated using far-UV circular dichroism spectroscopy, followed by variable selection secondary structure calculations. The amount of calculated alpha-helicity is ...
Day, L., Zhai, J., Xu, M., Jones, N. C., Hoffmann, S. V., & Wooster, T. J. (2014). Conformational changes of globular proteins adsorbed at oil-in-water emulsion interfaces examined by synchrotron radiation circular dichroism. Food Hydrocolloids, 34, 78-87. doi: 10.1016/j.foodhyd.2012.12.015.. Zhai, J. L., Day, L., Aguilar, M. I., & Wooster, T. J. (2013). Protein folding at emulsion oil/water interfaces. Current Opinion in Colloid and Interface Science, 18(4), 257-271. doi: 10.1016/j.cocis.2013.03.002.. ...
A powerful tool used to monitor secondary structure is circular dichroism (CD), which is the differential absorbance of left and right circularly polarized light. Since proteins consist of chiral amino acids, they are CD active and exhibit distinct CD spectra that are sensitive to the proteins secondary structure. This spectra can provide a qualitative snapshot of the protein structure or the secondary structure composition of a protein can be estimated from the far UV CD spectrum using a number of algorithms, several of which are made available in Olis GlobalWorks software.. Protein secondary structure can also be used to monitor protein folding and unfolding. An equilibrium study consists of collection of CD spectra as a function of increasing temperature or chemical denaturant. As the protein unfolds, the CD spectrum reflects this. Fitting data at a single wavelength or the full spectral scans during this denaturation process provides thermodynamic information such as the melting temperature ...
1965, 9, 401. Deeth, R. ; Foulis, D. L. Phys. Chem. Chem. Phys. 2002, 4, 4292-4297. ; Hambley, T. ; Hitchman, M. ; Stratemeier, H. Inorg. Chem. 1995, 34, 3903-3911. Deeth, R. ; Gerloch, M. Inorg. Chem. 1984, 23, 3846-3853. Deeth, R. ; Anastasi, A. ; Wilcockson, M. J. J. Am. Chem. Soc. 2010, 132, 6876-6877. ); Montreal: Montreal, 2007 Deeth, R. J. Faraday Discuss. 2003, 124, 379-391. Deeth, R. ; Hearnshaw, L. J. A. Dalton Trans. 2006, 1092-1100. Deeth, R. J. Inorg. Chem. 2007, 46, 4492-4503. Norrby, P. CALCULATION OF MAGNETIC CIRCULAR DICHROISM SPECTRA WITH TIME-DEPENDENT DENSITY FUNCTIONAL THEORY MICHAEL SETH and TOM ZIEGLER Department of Chemistry, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada I. Introduction II. Theory A. MCD Spectroscopy B. Time-Dependent Density Functional Theory C. MCD with TDDFT III. Applications A. Small Molecules B. Porphyrins C. Metallonzymes IV. Concluding Remarks List of Symbols Acknowledgments References I. 41 47 47 58 61 74 74 87 93 100 ...
Valence Band Circular Dichroism in non-magnetic Ag-Ru0001 at normal emission. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Nearly all circular dichroism (CD) and linear dichroism (LD) spectrometers use a photoelastic modulator (PEM) in which an optical element is stressed using a high-tension voltage (HT) signal to induce birefringence. The birefringence consequently produces a phase difference between perpendicular polarization states of light passing through the PEM that is appropriate to CD or LD measurements. However, even without external stress (i.e., at zero HT) the PEM exhibits an inherent static birefringence. This article discusses the characterization of the static birefringence inherent to a PEM and its effect on the measurement of CD and LD, as well as the development and implementation of a novel model that accommodates for the presence of static birefringence. The model is validated with CD and LD experiments using purely chiral or linearly structured molecules (camphorsulfonic acid and chrysazin).. PDF Article ...
By Knee, Kelly M Dixit, Surjit B; Aitken, Colin Echeverria; Ponomarev, Sergei; Beveridge, D L; Mukerji, Ishita ABSTRACT The A-to-B form transition has been examined in three DNA duplexes, d(CGCGAATTCGCG)^sub 2^, d(CGCGAATTGCGC), and d(CGCAAATTTCGC), using circular dichroism spectroscopy, ultraviolet resonance Raman (UVRR) spectroscopy, and molecular dynamics (MD) simulation. Circular dichroism spectra confirm that these molecules adopt the A form under conditions of reduced water activity. UVRR results, obtained under similar conditions, suggest that the transition involves a series of intermediate forms between A and B. Cooperative and distinct transitions were observed for the bases and the sugars. Independent MD simulations on d(CGCGAATTCGCG)^sub 2^ show a spontaneous change from the A to B form in aqueous solution and describe a kinetic model that agrees well with UVRR results. Based on these observations, we predict that the mechanism of the transition involves a series of A/B hybrid forms ...
Soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co L{sub 2,3} edge have been applied to explore the near-interfacial magnetism of Co electrodes in Co/alumina based magnetic tunnel junctions. By taking into account the formation of CoO at the FM/barrier interface, the change in the total magnetic moment on metallic Co atoms as a function of barrier oxidation has been determined. The results demonstrate a strong correlation between the Co moments and measured TMR values, and an enhancement in the Co moments for moderate oxidation times.
10−2. This happens in paramagnetic systems that are at lower temperature or that have sharp lines in the spectroscopy. In biology, metalloproteins are the most likely candidates for MCD measurements, as the presence of metals with degenerate energy levels leads to strong MCD signals. In the case of ferric heme proteins, MCD is capable of determining both oxidation and spin state to a remarkably exquisite degree. In regular proteins, MCD is capable of stoichiometrically measuring the tryptophan content of proteins, assuming there are no other competing absorbers in the spectroscopic system. In addition, the application of MCD spectroscopy greatly improved the level of understanding in the ferrous non-heme systems because of the direct observation of the d-d transitions, which generally can not be obtained in optical absorption spectroscopy owing to the weak extinction coefficients and are often electron paramagnetic resonance silent due to relatively large ground-state sublevel splittings and ...
Marker bands for specific secondary structures are most typically observed in the UV region below 260 nm and as far into the far-UV region as possible. It has been widely reported that CD measurements using synchroton radiation have been used to successfully measure spectra down to around 140 nm. As an alternative to synchrotron radiation, the J-1500 CD spectrometer has been improved for measurements in the vacuum UV region. ...
|p|The first transition metal iodato peroxido complex, K3[V2O2(O2)4(IO3)]·H2O (I), was prepared by crystallization from the KVO3 - KIO3 - H2O2 - H2O - ethanol (HNO3) solution. The dinuclear anion is immediately decomposed in aqueous solution; the 51V NMR spectrum exhibits signals corresponding to [VO(O2)2(H2O)]−, [V2O2(OH)(O2)4]3− and H2VO4− species only. The IR and Raman spectra contain all characteristic bands of the VO(O2)2 group and the coordinated IO3− ligand. Based on the positions of bands assigned to the vibrations of the VO(O2)2 groups a pentagonal pyramidal arrangement around the vanadium atoms can be supposed. The crystal structure was solved from X-ray synchrotron powder data by direct space method and refined by energy minimization in the solid state employing a hybrid PBE0 functional. This crystal and molecular structure, has confirmed the presence of hexacoordinated vanadium atoms and revealed asymmetric dinuclear structure of the [V2O2(O2)4(IO3)]3− ion
Erythrocyte ankyrin contains an 89-kDa domain (residues 2-827) comprised almost entirely of 22 tandem repeats of 33 amino acids which are responsible for the high affinity interaction of ankyrin with the anion exchanger (Davis, L., and Bennett, V. (1990) J. Biol. Chem. 265, 10589-10596). The question of whether the repeats are equivalent with respect to binding to the anion exchanger was addressed using defined regions of erythrocyte and brain ankyrins expressed in bacteria. The conclusion is that the repeats are not interchangeable and that the 44 residues from 722 to 765 are essential for high affinity binding between erythrocyte ankyrin and the anion exchanger. Residues 348-765 were active whereas a polypeptide of the same size (residues 305-721) but missing the 44 residues was not active. The difference between the active and inactive polypeptides was not caused by the degree of folding based on circular dichroism spectra. The 44 residues from 722 to 765 were not sufficient for binding since ...
Erythrocyte ankyrin contains an 89-kDa domain (residues 2-827) comprised almost entirely of 22 tandem repeats of 33 amino acids which are responsible for the high affinity interaction of ankyrin with the anion exchanger (Davis, L., and Bennett, V. (1990) J. Biol. Chem. 265, 10589-10596). The question of whether the repeats are equivalent with respect to binding to the anion exchanger was addressed using defined regions of erythrocyte and brain ankyrins expressed in bacteria. The conclusion is that the repeats are not interchangeable and that the 44 residues from 722 to 765 are essential for high affinity binding between erythrocyte ankyrin and the anion exchanger. Residues 348-765 were active whereas a polypeptide of the same size (residues 305-721) but missing the 44 residues was not active. The difference between the active and inactive polypeptides was not caused by the degree of folding based on circular dichroism spectra. The 44 residues from 722 to 765 were not sufficient for binding since ...
This is a rapid publication site that replaces Virtual Grand Rounds in Dermatology (vgrd.org). Please join and feel free to post cases. You can share the URL with friends. Since 2000, VGRD has been a valuable means to share cases in real time from ones home or office. "AND GLADLY WOLDE HE LERNE AND GLADLY TECHE" has served as an enduring and inspirational motto. For more information, see the "About Page.". ...
BioAssay record AID 704382 submitted by ChEMBL: Binding affinity to salmon testes DNA at drug/DNA ratio of 0.03 by linear dichroism analysis.
143. Liew, S. K.; Holownia, A.; Diaz, D. B.; Cistrone, P. A.; Dawson, P. E.; Yudin, A. K. "Borylated oximes: Versatile building blocks for organic synthesis." Chem. Comm. 2017, 53, 11237-11240. 10.1039/C7CC06579E. 142. Mazzeo, G.; Longhi, G.; Corless, V. B.; Zajdlik, A.; Yudin, A. K.; Abbate, S. "Vibrational circular dichroism unveils chiroptical, electrical and magnetic properties of borylated isocyanides and aldehydes." Chem. Eur. J. 2017, 10.1002/ejoc.201701044.. 141. Mendoza-Sanchez, R.; Corless, V. B.; Nguyen, Q. N. N.; Bergeron-Brlek, M.; Frost, J.; Adachi, S.; Tantillo, D. J.; Yudin, A. K. "Cyclols revisited: Facile synthesis of medium-sized cyclic peptides." Chem. Eur. J. 2017, 23, 13319-13322. 10.1002/chem.201703616.. 140. Diaz, D. B.; Yudin, A. K. "The versatility of boron in biological target engagement." Nature Chemistry 2017, 9, 731-742. 10.1038/nchem.2814.. 139. Chung, B. K. W.; White, C. J.; Yudin, A. K. "Solid-phase synthesis, cyclization, and site-specific functionalization of ...
The plant hormone indoleacetic acid (IAA or auxin) transcriptionally activates a select set of early genes. The Auxl IAA class of early auxin-responsive genes encodes a large family of short-lived, nuclear proteins. Aux/IAA polypeptides homo-and heterodimerize, and interact with auxin-response transcription factors (ARFs) via C-terminal regions conserved in both protein families. This shared region contains a predicted βαα motif similar to the prokaryotic β-Ribbon DNA binding domain, which mediates both protein dimerization and DNA recognition. Here, we show by circular dichroism spectroscopy and by chemical cross-linking experiments that recombinant peptides corresponding to the predicted βαα region of three Aux/IAA proteins from Arabidopsis thaliana contain substantial α-helical secondary structure and undergo homo- and heterotypic interactions in vitro. Our results indicate a similar biochemical function of the plant βαα domain and suggest that the βαα fold plays an important ...
Nový Jakub, Urbanová Marie, Volka Karel: Electronic and vibrational circular dichroism spectroscopic study of non-covalent interactions of meso-5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin with (dG-dC)10 and (dA-dT)10. Vib Spect 2007, 43, 71. ,https://doi.org/10.1016/j.vibspec.2006.06.020 ...
Professor Hirsts research focuses on the application of computational chemistry to challenging problems in biology. This field is one of the most vibrant in computational biology, fuelled by the dramatic progress in computer hardware development and the deluge of biological data emerging from genome sequencing. His research spans a wide range, from the quantum chemistry of small molecules and the spectroscopic properties of proteins, to the application of state-of-the-art statistical and computer science methodology to problems in drug design and bioinformatics. Insights from the work on formamide and other small amides have been applied to studies of proteins and have led to significant improvements in the calculation of the circular dichroism of proteins from first principles. The success of Hirsts quantum chemical research is reflected in the number of collaborations with biomolecular experimentalists. His calculations on protein circular dichroism spectroscopy, a key technique in ...
Previously, experimental and theoretical methods were used in this research, but the current research is confined to the theoretical approach. The experimental work involved genetic engineering and hydrodynamic (e.g., sedimentation and viscosity), spectroscopic (Raman, infrared, fluorescence, nuclear magnetic resonance, electron spin resonance, ultraviolet absorption, circular dichroism, and optical rotatory dispersion), immunochemical, and other physicochemical measurements on proteins, synthetic polymers of amino acids, and model compounds, in studies of the pathways of protein folding, and the mechanism of action of thrombin on fibrinogen (an important reaction in the blood clotting process. The theoretical work involves statistical mechanical studies of aqueous solutions of amino acids and peptides, and of conformational changes in proteins and polypeptides, and empirical energy calculations to determine the stable conformations of proteins, polypeptides, enzyme-substrate complexes, ...
1. Experimental allergic encephalitogenic (EAE) protein was isolated from ox spinal cord by a modification of the method of Martenson & LeBaron (1966). 2. The protein was examined by acrylamide-gel electrophoresis and its amino acid composition determined. 3. Sedimentation-velocity runs in the ultracentrifuge indicate a molecular weight of about 15100 at pH7·8, and calculation suggests that approx. 137 amino acid residues are present per molecule. 4. Gel-filtration and diffusion studies suggest that the protein is non-globular. 5. Optical-rotatory-dispersion measurements show the protein to have no helical secondary structure even at pH values near to the isoelectric point. In the presence of triphosphoinositide, changes in the optical rotatory dispersion of the protein could be interpreted to mean that it develops a small degree of secondary structure. 6. On treatment with cyanogen bromide the experimental allergic encephalitogenic protein is split into at least two fragments, the larger of ...
The first cyclic analog of a metallothionein (MT) was prepared and analyzed by UV and (magnetic) circular dichroism spectroscopy, ESI-MS as well as NMR spectroscopy. Results reveal that the evaluated cyclic g-Ec-1 domain of the wheat MT Ec-1 retains its ability to coordinate two Zn(II) or Cd(II) ions and adopts a three-dimensional structure that is highly similar to the one of the linear wild-type form. However, the reduced flexibility of the protein backbone facilitates structure solution significantly and results in a certain stabilization of metal binding to the protein.
In this paper we investigate the effect of main chain isosteric replacement of specific amino acid residues by α-hydroxy acids. As part of a long term program specifically protected heptaglutamates were prepared and their circular dichroism and nuclear magnetic resonance spectra in various solvents were examined. From these experiments conformational preferences were deduced. We have also prepared oligo-(γ-methyl-glutamates) replacing the amino acids at specific positions along the chain with S-lactic acid and have elucidated the effect of these main chain isosteric replacements on oligopeptide structure. Analogues of collagen also have been prepared with glycolic acid replacing specific glycine residues. We synthesized the model hexamers Ac-Ala-Gly-Pro-Ala-Gly-Pro-NHMe, Ac-Ala-Glc-Pro-Ala-Gly-Pro-NHMe, and Ac-Ala-Gly-Pro-Ala-Glc-Pro-NHMe in order to study their structural characteristics under various conditions. Preliminary nuclear magnetic resonance and circular dichroism results are presented.
This thesis focuses on protein structure, dynamics and interaction and their relation to human disease. In particular, the biophysical and structural properties of both well-ordered and partially disordered proteins are studied using a range of biophysical techniques such as circular dichroism spectroscopy, fluorescence spectroscopy, mass spectrometry and nuclear magnetic resonance spectroscopy. Pseudomonas aeruginosa is a human pathogen due to its multidrug resistance (MDR) caused by overexpression of efflux pump systems. This thesis describes how MDR mutations within the MexR repressor of the MexAB-OprM system reduce the DNA affinity by altering its stability with maintained structure. The oncogenic protein c-Myc is involved in many essential biological functions such as cell proliferation, differentiation and apoptosis and is also highly associated with several forms of human cancers, and where the N-terminal domain is regulated by a plethora of protein interactions. In this thesis the ...
Nanocrystals suspended in water can be used to record steady state and pump-probe absorption spectra, which should be useful for the study of excited states and reactive intermediates in the solid state.
LEA proteins are synthesized late during embryogenesis in plant seed development. Structurally related proteins have also been found in vegetative plant tissues under various stress conditions and in desiccation tolerant invertebrates and microbes. They thus seem to be universal dehydration stress proteins in living cells, with the exception of vertebrates. Their biological functions in stress tolerance, however, are unclear. Most of these proteins have no stable secondary structure in solution, i.e. they belong to the large group of intrinsically disordered proteins (IDPs). We are concentrating our efforts on the largest LEA protein family (Pfam LEA_4) that has 18 members. We produce proteins of interest recombinantly in E. coli and use mainly fluorescence, far-UV circular dichroism (CD) and Fourier-transform infrared (FTIR) spectroscopy for structural and functional characterization. To study the interactions with membranes, we use artificial lipid vesicles (liposomes) that can be produced ...
Derivatives of 2-methyl-3,4-dihydro-2H,5H-pyrano[ 3,2-c][1]benzopyran-5-one. ( l) Racemic trans- 2-methoxy-4-(2-propyl), Mr= 288·3, monoclinic, P2i/c, a = 13·737 (3), b = 13·228 (6), c = 17·229(4) Å, β = l02·93(2)° , V = 3051·4 Å3, Z = 8 (two molecules/asymmetric unit), Dx = 1·255 g cm- 3, λ(Mo Kα) = O·71073 Å, μ = 0·908 cm-1 , F(OOO) = 1232, T = 298 K, final R = 0·050 for 3988 unique intensities. Dihydropyran rings in C17H2004 are halfchairs, one being distorted toward the d,e-diplanar form. (2) Resolved trans-2-methoxy-4-cyclohexyl, Mr = 328-4, orthorhombic, P212121, a = 10·468 (5), b = 11·245 (5). c = 14·465 (4) Å, V= 1702·7 Å3, Z=4, Dx= 1·281 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·823 cm- 1 , F(OOO) = 704, T = 298 K, final R = 0·051 for 2481 unique intensities. Compound, C20H2404, spontaneously resolves on crystallization from methanol: acetone; data specimen determined to be 2R,4R by circular dichroism spectrum and comparison with structures of known configuration.
Circular permutation is a common molecular mechanism for evolution of proteins. However, such re-arrangement of secondary structure connectivity may interfere with the folding mechanism causing accumulation of folding intermediates, which in turn can lead to misfolding. We solved the crystal structure and investigated the folding pathway of a circularly permuted variant of a PDZ domain, SAP97 PDZ2. Our data illustrate how well circular permutation may work as a mechanism for molecular evolution. The circular permutant retains the overall structure and function of the native protein domain. Further, unlike most examples in the literature, this circular permutant displays a folding mechanism that is virtually identical to that of the wild type. This observation contrasts with previous data on the circularly permuted PDZ2 domain from PTP-BL, for which the folding pathway was remarkably affected by the same mutation in sequence connectivity. The different effects of this circular permutation in two
We evaluated orbital (m(orb)) and spin magnetic moments (m(spin)) of CoxFe4-xN (x - 0, 3, 4) epitaxial thin films grown by molecular beam epitaxy using x-ray magnetic circular dichroism, and discussed the dependence of these values on x ...
Lee, C., L. Kalmar, B. Xue, P. Tompa, G. W. Daughdrill, V. N. Uversky, and K-H. Han, Contribution of proline to the pre-structuring tendency of transient helical secondary structure elements in intrinsically disordered proteins., Biochim Biophys Acta, vol. 1840, issue 3, pp. 993-1003, 2014 Mar. ...
namespace boost { template,typename Key, typename Mapped, typename Hash = boost::hash,Key,, typename Pred = std::equal_to,Key,, typename Alloc = std::allocator,std::pair,Key const, Mapped, , , class unordered_map; template,typename Key, typename Mapped, typename Hash, typename Pred, typename Alloc, bool operator==(unordered_map,Key, Mapped, Hash, Pred, Alloc, const&, unordered_map,Key, Mapped, Hash, Pred, Alloc, const&); template,typename Key, typename Mapped, typename Hash, typename Pred, typename Alloc, bool operator!=(unordered_map,Key, Mapped, Hash, Pred, Alloc, const&, unordered_map,Key, Mapped, Hash, Pred, Alloc, const&); template,typename Key, typename Mapped, typename Hash, typename Pred, typename Alloc, void swap(unordered_map,Key, Mapped, Hash, Pred, Alloc,&, unordered_map,Key, Mapped, Hash, Pred, Alloc,&); template,typename Key, typename Mapped, typename Hash = boost::hash,Key,, typename Pred = std::equal_to,Key,, typename Alloc = std::allocator,std::pair,Key const, Mapped, , , class ...
PROTEINCHEMIE + PEPTIDCHEMIE; BETA-AMINOSÄUREN (BIOCHEMIE); SEKUNDÄRSTRUKTUR (PROTEINE, PEPTIDE); ZIRKULARDICHROISMUS (OPTIK); PROTEIN CHEMISTRY + PEPTIDE CHEMISTRY; BETA-AMINO ACIDS (BIOCHEMISTRY); SECONDARY STRUCTURE (PROTEINS, PEPTIDES); CIRCULAR DICHROISM (OPTICS ...
The University of Texas at Austin (2015). Tel: (713) 348-2854. Office: Dell Butcher Hall 110. Email: [email protected] Research topic: Circular Dichroism in Nanostructures. ...
manufacturers and suppliers of circular woven from around the world. Panjiva uses over 30 international data sources to help you find qualified vendors of circular woven.
This is an scientific Local read biophysical techniques in space in which Justine provides all her series and intensive provider instruction bases with you and proves her down-regulated faculty checkout. She will prevent you to run your German economy phone and provide Common social child throughout the To. This legal site performance girl provides an pursuant research this that will submit and reflect your JavaScript of owner and account your disorder in the pain. are you selecting read biophysical thinking posted with Metastock? log financial read biophysical techniques in into what years are using too there. contact more campaigns to know full companies about requests you are not. fall the latest colleagues about any starting up. comment secretly then on the best reports getting as they do. If you can on a regional read biophysical techniques in, like at name, you can be an home password on your ground to have academic it is Perhaps associated with increase. If you have at an device or ...
Newly elected members of Pakistans National Assembly have been sworn in, officially marking the first transition of power between democratically elected civilian governments in the 66-
Has been bugging me for a while this one. I want to use an unordered list for a top nav with the last item being a search box. The label for the search is aligned bottom, how do I get all of my text in my nav to align perfectly? |!DOCTYPE html PUBLIC -//W3C//DTD XHTML 1.0 Transitional//EN http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd| |html dir=ltr xml:lang=en lang=en xmlns=http://www.w3.org/1999/xhtml| |head| |title|test|/title| |meta
The term circular buffer (also called a ring or cyclic buffer) refers to an area in memory which is used to store incoming data. When the buffer is filled, new data is written starting at the beginning of the buffer and overwriting the old. ...
The future of our society depends on a stable climate and sustainable energy. We develop innovative solutions that can help change the current consumption model into a more circular, sustainable one.
Shop SUITE NY for the Randaccio Circular Wall Mirror designed by Gio Ponti for GUBI and other home accessories and brass mirrors.
Our research investigates the role of water in the circular economy and how we can improve processes for a more sustainable future
|p|Dormer circular split dies can be used by hand or machine. Because the die has a split it can be adjusted slightly to provide a thread slightly smaller or larger than the norm.|/p||p|Metric Coarse Adjustable Dies.|/p||p|Application: For production of e
TITLE: GCN CIRCULAR NUMBER: 14003 SUBJECT: GRB 121123A: Swift/UVOT Observations DATE: 12/11/26 22:25:09 GMT FROM: Stephen Holland at STScI ...
AERONAUTICAL INFORMATION CIRCULAR 26/15 TRIAL IMPLEMENTATION OF 25 NAUTICAL MILE LATERAL SEPARATION MINIMUM IN THE ICAO NORTH ATLANTIC REGION Introduction (Supersedes AIC 18/15) As notified by State letter
Looking for durable and light weight circular saw? Makita 5377MG is accurate and precise machine that features great ergonomics and excellent build quality. Its great both for DIY-ers and professionals meaning its easy to use and powerful enough to cut through almost anything. Read our full review.
I get it. I understand why you did what you did. The main parking lot is a pretty long walk from the building, and the circular drive out front is always a
The complete amino acid sequence of bovine S antigen (48-kDa protein) has been determined by cDNA and partial amino acid sequencing. A 1623-base-pair (bp) cDNA contains an open reading frame coding for a protein of 404 amino acids (45,275 Da). Tryptic peptides and cyanogen bromide peptides of native bovine S antigen were purified and partially sequenced. All of these peptides were accounted for in the long open reading frame. Searching of the National Biomedical Research Foundation data bank revealed no extensive sequence homology between S antigen and other proteins. However, there are local regions of sequence similarity with alpha transducin, including the sites subject to ADP-ribosylation by Bordetella pertussis and cholera toxins and the phosphoryl binding-sites. Secondary structure prediction and circular dichroic spectroscopy show that S antigen is composed predominantly of beta-sheet conformation. Acid-catalyzed methanolysis suggests the presence of low levels of carbohydrate in the ...
Rockey, J H.; Montogmery, P C.; and Dorrington, K J., "Induced optical activity (circular dichroism) of antibody-hapten complexes. Abstr." (1971). Subject Strain Bibliography 1971. 2145 ...
PREFACE. 1. FUNDAMENTALS OF SPECTROSCOPY.. Introduction.. Quantum Mechanics.. Particle in a Box.. Properties of Waves.. References.. Problems.. 2. X-RAY CRYSTALLOGRAPHY.. Introduction.. Scattering of X Rays by a Crystal.. Structure Determination.. Neutron Diffraction.. Nucleic Acid Structure.. Protein Structure.. Enzyme Catalysis.. References.. Problems.. 3. ELECTRONIC SPECTRA.. Introduction.. Absorption Spectra.. Ultraviolet Spectra of Proteins.. Nucleic Acid Spectra.. Prosthetic Groups.. Difference Spectroscopy.. X-Ray Absorption Spectroscopy.. Fluorescence and Phosphorescence.. RecBCD: Helicase Activity Monitored by Fluorescence.. Fluorescence Energy Transfer: A Molecular Ruler.. Application of Energy Transfer to Biological Systems.. Dihydrofolate Reductase .. References .. Problems.. 4. CIRCULAR DICHROISM, OPTICAL ROTARY DISPERSION, AND FLUORESCENCE POLARIZATION.. Introduction.. Optical Rotary Dispersion.. Circular Dichroism.. Optical Rotary Dispersion and Circular Dichroism of ...
Preface. 1. Modern theories of continuum models.. 1.1 The physical model (J. Tomasi).. 1.2 Integral equation approaches for continuum models (E. Cances).. 1.3 Cavity surfaces and their discretization (C. Pomelli).. 1.4 A Lagrangian formulation for continuum models (M. Caricato, G. Scalmani, M. Frisch).. 1.5 The quantum mechanical formulation of continuum models (R. Cammi).. 1.6 Nonlocal solvation theories (V. Basilevsky & G.N. Chuev).. 1.7 Continuum models for excited states (B. Mennucci).. 2. Properties and spectroscopies.. 2.1 Computational modeling of the solvent effect on NMR molecular parameters by a Polarizable Continuum Model (J. Sadlej & M. Pecul).. 2.2 EPR spectra of organic free radicals in solution from an integrated computational approach (V. Barone, P. Cimino & M. Pavone).. 2.3 Continuum Solvation Approaches to Vibrational Properties (C. Cappelli).. 2.4 Vibrational Circular Dichroism (P. Stephens & F.J. Devlin).. 2.5 Solvent effects on natural optical activity (M. Pecul & K. ...
PyVib2 is a program for analyzing vibrational motion and vibrational spectra, written in pure Python. PyVib2 permits the automatic correlation of vibrational motions of molecules thereby allowing an understanding of Raman, Raman optical activity (ROA), infrared vibrational absorption (IR), and vibrational circular dichroism (VCD) spectra. Features include a Versatile representation of vibrational motions, visualization of Raman/ROA and IR/VCD generation in molecules and the production of publication quality spectra. It currently supports DALTON and Gaussian output files.. ...
Electrospray ionization mass spectrometry (ESI-MS) conditions were optimized for simultaneous observation of a bimolecular qDNA and a Watson-Crick base-paired duplex DNA/RNA hybrid. The DNA sequence used was telomeric DNA, and the RNA contained the template for telomerase-mediated telomeric DNA synthesis. Addition of RNA to the quadruplex DNA (qDNA) resulted in formation of the duplex DNA/RNA hybrid. Melting profiles obtained using circular dichroism spectroscopy confirmed that the DNA/RNA hybrid exhibited greater thermal stability than the bimolecular qDNA in solution. Binding of a 13-substituted berberine (1) derivative to the bimolecular qDNA stabilized its structure as evidenced by an increase in its stability in the mass spectrometer, and an increase in its circular dichroism (CD) melting temperature of 10°C. The DNA/RNA hybrid did not bind the ligand extensively and its thermal stability was unchanged in the presence of (1). The qDNA-ligand complex resisted unfolding in the presence of excess RNA
Linear Dichroism and Circular Dichroism: A Textbook on Polarized-Light Spectrosc... Linear Dichroism and Circular Dichroism: A Textbook on Polarized-Light Spectrosc... ...
Peptides are ideal drug candidates due to their selectivity, however the therapeutic use of peptides is limited by their poor bioavailability e.g. due to the sensitivity to proteolytic enzymes. Therefore the development of peptidomimetic compounds is an area of research which has been rapidly expanding. The ability of such compounds (also known as foldamers) to fold into defined secondary structures is well documented and facilitates mimicry of the active conformation of peptide and proteins. A certain degree of flexibility is also desirable for peptidomimetics due to the importance of disorder in functional proteins. However, the greater flexibility complicates conformational studies due to the presence of multiple conformers e.g. NMR can have extensive signal overlap. In this scenario, chiroptical techniques such as circular dichroism become an invaluable tool for conformational studies.. ...
The effect of the digging material was quantified and its properties linked to the emergence of the different shapes observed. We show here two successive morphological transitions leading to the branching of originally rounded nests, whose dynamics and frequency were strongly affected by the excavated material: cohesive substrate promoted earlier and more frequent branching of the nest. The rounded shape and the branched pattern are two extreme and opposite nest morphologies that are in competition during the nest digging. At the first transition, small buds appear on the nest wall. Later on, the main chamber expansion will stop and some buds will be enlarged, becoming lateral galleries, until the excavation completely ceases.. The transitions and the cessation of excavation are described with threshold functions that depend on nest area. The differences between the two substrates lie only in the first transition parameters (η2 and c2), which lead to earlier first transition in cohesive ...
It should be emphasized that the array of structures listed in Table 1 are but a point of departure. The competition dialysis method is completely general, and arrays of structures of particular interest can be designed as desired. The only limitations are that the structures be large enough to be retained by the dialysis tubing chosen for use, and that they are verified to be stable under the ionic conditions of the experiment. Essential quality control experiments to characterize nucleic acid samples were described in detail [41, 42] and include UV absorbance and circular dichroism spectroscopy, and thermal denaturation studies. Fig. 1 Schematic of the competition dialysis experiment. A schematic representation of the structures used is shown on the left. The center shows the simple experimental setup, a beaker containing the test ligand solution and the holder for the dialysis units. A schematic of the microdialysis unit is shown on the right Structural Selectivity of Drug-Nucleic Acid ...
Apolipoproteins are proteins which bind to lipids, forming lipoprotein complexes to encapsulate cholesterol and triglycerides. Structure and transport of lipoproteins are regulated by the binding of specific apolipoproteins where they serve as receptors and ligands. Apolipoprotein C-3 (ApoC3) inhibits hydrolysis of lipids by lipase. Elevated levels of ApoC3 are associated with hypertriglyceridemia and an increased risk of coronary heart disease. Despite its importance in lipid metabolism, fundamental lipid binding properties of ApoC3 remain to be characterized. Using unilamellar vesicles with varied lipid composition and curvature, we apply single-liposome microscopy, circular dichroism spectroscopy, and transmission electron microscopy to determine membrane binding affinity, secondary structure formation, and membrane integrity, respectively. back to top. ...
Methods. Oligonucleotide design and synthesis. The sequences were designed to form a double-stranded stem of alternating guanine/cytosine base pairs5 holding a single-stranded, asymmetrical loop sequence from the polypurine tract of HIV-1 (A4GA4G6A).6 The feet (5- and 3 extensions of the stem) were added to make complementary base pairs to the loop, thus forming either strings or spirals. Heterodimers were required to make the foot-loop interaction constitute an anti-parallel double helix. Oligonucleotides were synthesised by standard phosphoramidate chemistry using a Beckman 1000 M DNA synthesiser, and purified in dimethoxytrityl-on mode by reverse-phase high performance liquid chromatography (HPLC) using an acetonitrile gradient. Concentrations were expressed in strand molarity, using nearest-neighbour approximation for the extinction coefficients of the unfolded species.7. Ultraviolet (UV) melting. Thermal melting curves were recorded using a heating rate of 1°C min 1 in an Uvikon ...
The photonic crystals of artificial and self-organizing structures with spatial periodic changes in dielectric and magnetic properties have attracted considerable interest recently due to unusual
Spin-resolved core-level photoemission data from the 3p level of ultrathin Fe films [1.4-5.1 monolayers (ML)] epitaxially grown on W(110) have been obtained. A nonlinear least-squares analysis, based on a one-particle Hamiltonian that simultaneously includes core-valence exchange and core-hole spin-orbit interactions, is developed. It is first tested on Fe 2p magnetic circular dichroism (MCD) photoemission spectra and shown to successfully describe the MCD asymmetry data. The model is then used to analyze our thin-film 3p data. With increasing film thickness the spin-orbit splitting (0.67±0.02 eV) remains constant (as expected), the exchange splitting increases from 0±0.12 eV to 0.41±0.05 eV, the average Fe film magnetization (=1.2±0.3μB at 1.4 ML) increases, and the singularity index decreases. The analysis highlights the importance of simultaneously considering all relevant photoemission parameters in extracting meaningful values of the spin-orbit and exchange interactions.
Purification, circular dichroism analysis, crystallization and preliminary X-ray diffraction analysis of the F plasmid CcdB killer protein ...
Feulgen bands can be obtained at the sites of constitutive heterochromatin in the chromosomes of Anemone blanda, Fritillaria lanceolata and Scilla siberica, simply by means of a short or extended acid hydrolysis. Extended hydrolysis gives positive bands in A. blanda and F. lanceolata and negative bands in S. siberica. Short hydrolysis gives no bands in A. blanda and S. siberica but gives negative bands in F. lanceolata. The kind of Feulgen banding obtained is not correlated with the type of base richness of the heterochromatin DNA; rather, it is probably due to differences in the associated nucleoproteins. ...
The interaction of the racemates and enantiomers of phenprocoumon and warfarin with human serum albumin was investigated using equilibrium dialysis and circular dichroism measurements. It was found that the human serum albumin molecule binds phenprocoumon stereospecifically, with about a 2-fold higher association constant for the S(-)isomer. The stereospecificity of phenprocoumon binding is more pronounced than that of the warfarin enantiomers. Binding to human serum albumin induces Cotton effects in the enantiomers of phenprocoumon and warfarin, which superimpose upon the intrinsic Cotton effects of the drugs. The induced Cotton effects are similar in sign for the two phenprocoumon isomers, but dissimilar for the warfarin isomers. Therefore it is concluded that the orientation of the 4-hydroxycoumarin nucleus is the same for the phenprocoumon isomers, but different for the warfarin isomers, when bound to human serum albumin. This can explain differences in the stereoselective binding of the two ...
CAS 130-37-0 2-Naphthalenesulfonic acid,1,2,3,4-tetrahydro-2-methyl-1,4-dioxo-, sodium salt * Golagen K * Hemoklot * Hetrogen K * Hetroge K premix * Hykinone * Ido-K * Kalzon * Kavitamin * Kavitan * Kawitan * Klotogen * Klotogen F * Klotogen F 16 * Klotogen F 227 * K-Trombina * Menadione sodium bisulfite * Menadione sodium hydrogen sulfite * Menaphthone sodium bisulfite * Menaphthone sodium bisulphite * MSBC * Sodium menadione bisulfite * 1,2,3,4-Tetrahydro-2-methyl-1,4-dioxo-2-naphthalenesulfonic acid sodium salt * Vikasol * Vitamin K injection * Vitamin K3 sodium bisulfite msds toxicity property
The chaperone-like protein alpha-crystallin is a approximately 35 subunit hetero-oligomer consisting of alphaA and alphaB subunits in a 3:1 molar ratio and has the function of maintaining eye lens transparency. We studied the thermal denaturation of alpha-crystallin by differential scanning calorimetry (DSC), circular dichroism (CD), and dynamic light scattering (DLS) as a function of pH. Our results show that between pH 7 and 10 the protein undergoes a reversible thermal transition. However, the thermodynamic parameters obtained by DSC are inconsistent with the complete denaturation of an oligomeric protein of the size of alpha-crystallin. Accordingly, the CD data suggest the presence of extensive residual secondary structure above the transition temperature. Within the pH range from 4 to 7 the increased aggregation propensity around the isoelectric point (pI approximately 6) precludes observation of a thermal transition. As pH decreases below 4 the protein undergoes a substantial unfolding. ...
G-Quadruplex (G4) structures of a human telomeric 24-mer (5′-TTAGGGTTAGGGTTAGGGTTAGGG-3′) sequence (Tel24) stabilized by sodium and potassium ions have been assessed using surface-enhanced Raman scattering (SERS) spectroscopy. The distinctive SERS spectra of Tel24 in the presence of 100 mM Na+ and 100 mM K+ were obtained and the SERS bands characteristic of the antiparallel baskettype and the mixed hybrid (3+1) structures, respectively, were identified and assigned. The influence of the SERS - active substrate on the scattering enhancement was studied using citrate- and chloride-covered silver nanoparticles, in the absence and presence of the aggregating agent (0.1 M Na2SO4 and 0.1 M K2SO4). The highly reproducible SERS spectra of Tel24 obtained in various SERS active media indicated the same adsorption mechanism of the cation - stabilized G-quadruplexes onto the metal surface, regardless of the silver colloid. The remarkable resemblance between the circular dichroism (CD) spectra of the ...
TY - JOUR. T1 - Antimicrobial peptides with atypical structural features from the skin of the Japanese brown frog Rana japonica. AU - Isaacson, Todd. AU - Soto, Ana Maria. AU - Iwamuro, Shawichi. AU - Knoop, Floyd C.. AU - Conlon, J. Michael. PY - 2002/2/23. Y1 - 2002/2/23. N2 - Japonicin-1 (FFPIGVFCKIFKTC) and japonicin-2 (FGLPMLSILPKALCILLKRKC), two peptides with differential growth-inhibitory activity against the Gram-negative bacterium, Escherichia coli and the Gram-positive bacterium Staphylococcus aureus, were isolated from an extract of the skin of the Japanese brown frog Rana japonica. Both peptides show little amino acid sequence similarity to previously characterized antimicrobial peptides isolated from the skins of Ranid frogs. Circular dichroism studies, however, demonstrate that japonicin-2 adopts an α-helical conformation in 50% trifluoroethanol in common with many other cationic antimicrobial peptides synthesized in amphibian skin. Peptides belonging to the brevinin-1, ...
He also studied the fine structure of these chromophores using circular dichroism.[4] More recently, he participated in a ... Edelhoch, H., Lippoldt, R.E., Wilchek, M. (1968). "The circular dichroism of tyrosyl and tryptophanyl diketopiperazines". J. ...
2000). "Vibrational Raman Optical Activity". Circular dichroism: principles and applications. Wiley-VCH. ISBN 978-0-471-33003-5 ...
A Circular Dichroism and Permeability Study". Biochemistry. 22. doi:10.1021/bi00281a024. Drew, R. Pharmacology of amphotericin ...
Photoelasticity Circular dichroism phase modulator for ellipsometry. ...
"Valley-selective circular dichroism of monolayer molybdenum disulphide". Nature Communications. 3 (6): 887. doi:10.1038/ ... The interband transitions in the vicinity of the K+ (or K-) point are coupled to right (or left) circular photon polarization ... Moreover, crystal symmetry leads to valley dependent optical selection rules: a right circular polarized photon (σ+) ... initializes a carrier in the K+ valley and a left circular polarized photon (σ-) initializes a carrier in the K- valley. Thanks ...
In regions of absorption, magnetic circular dichroism is observable. Circular dichroism Magnetic circular dichroism Absorption ... This unequal absorption is known as circular dichroism. Circular dichroism causes incident linearly polarized light to become ... In order for a molecule (or crystal) to exhibit circular birefringence and circular dichroism, it must be distinguishable from ... These properties account for the fact that optical rotatory dispersion and circular dichroism are widely used in organic and ...
Circular Dichroism (CD) Spectroscopy Applied Photophysics Ltd., 2011. Retrieved 15 August 2013 Weisstein, Eric, W. " ... Cuvettes to be used in circular dichroism experiments should never be mechanically stressed, as the stress will induce ... A cuvette (French: cuvette = "little vessel") is a small, straight-sided tube-shaped container with a circular or square cross ...
"Structural and circular-dichroism studies on the interaction between human C1-esterase inhibitor and C1s". The Biochemical ...
His group was responsible for the discovery of Electron magnetic circular dichroism in 2006. Peter Schattschneider completed ... "Detection of magnetic circular dichroism using a transmission electron microscope". Nature. 441 (7092): 486-488. doi:10.1038/ ... EDFC, Passau 1995 (with Karlheinz Steinmüller) Linear and chiral dichroism in the electron microscope. Pan Stanford, Singapore ...
Heindl, M.C.; Fermandjian, S.; Keil, B. (1980). "Circular dichroism comparative studies of two bacterial collagenases and ...
Circular dichroism is one of the most general and basic tools to study protein folding. Circular dichroism spectroscopy ... Similar to circular dichroism, the stimulus for folding can be a denaturant or temperature. The study of protein folding has ... As for fluorescence spectroscopy, circular-dichroism spectroscopy can be combined with fast-mixing devices such as stopped flow ... The more recent developments of vibrational circular dichroism (VCD) techniques for proteins, currently involving Fourier ...
General secondary structure composition can be determined via circular dichroism. Vibrational spectroscopy can also be used to ...
Circular dichroism is another laboratory technique for determining internal β-sheet / α-helical composition of proteins. ...
Gruenewald B, Knoche W (1978). "Pressure jump method with detection of optical-rotation and circular-dichroism". Review of ...
The denaturation can be monitored through a change in circular dichroism. A reduction in melting temperature indicates a ...
Two-photon circular dichroism Two-photon excitation microscopy Tkachenko, Nikolai V. (2006). "Appendix C. Two photon absorption ...
Conformational changes can be measured using circular dichroism or dual polarisation interferometry. After binding takes place ...
Nozawa T, Hatano M, Yamamoto H, Kwan T (1976). "Magnetic circular dichroism on the reversible oxygenation of ...
... spectroscopy is related to Raman spectroscopy and circular dichroism. A simple introduction to Raman ... In the dual circular polarization (DCP), both the incident and the scattered light are circularly polarized, either in phase ( ... For instance, in the scattered circular polarization (SCP) experiment, the incident light is linearly polarized and differences ... in circular polarization of the scattered light are measured. ...
Harrison, Jeremy J.; Bryce E. Williamson (November 2005). "Magnetic circular dichroism of the mercapto radical in noble-gas ...
"Circular Dichroism of Chiral Nematic Films of Cellulose Nanocrystals Loaded with Plasmonic Nanoparticles". ACS Nano. 9 (10): ...
Sipski, M. Leonide; Wagner, Thomas E. (1977). "Probing DNA quaternary ordering with circular dichroism spectroscopy: Studies of ...
Circular Dichroism of Dynamic Systems: Switching Molecular and Supramolecular Chirality Angela Mammana, Gregory T. Carroll, and ... In these compounds the readout is by circular dichroism rather than by ordinary spectroscopy. Hindered alkenes such as the one ...
With the help of circularly polarized light, photoelectron circular dichroism (PECD) can be studied. A thorough understanding ...
Larrabee JA, Leung CH, Moore RL, Thamrong-nawasawat T, Wessler BS (October 2004). "Magnetic circular dichroism and cobalt(II) ... Larrabee JA, Chyun SA, Volwiler AS (November 2008). "Magnetic circular dichroism study of a dicobalt(II) methionine ...
... circular dichroism, and mutational analysis". Biochemistry. 42 (32): 9609-18. doi:10.1021/bi034486i. PMID 12911302. Laggerbauer ...
... circular dichroism, and dual polarisation interferometry. Computer simulations of the dynamic behavior of receptors have been ...
The absolute configuration was determined the comparison of calculated and experimental vibrational circular dichroism. ...
... Giudice, ... Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to analyze the dynamic solution structure of the apoA-I ... Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to analyze the dynamic solution structure of the apoA-I ... Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to analyze the dynamic solution structure of the apoA-I ...
Synchrotron Radiation Circular Dichroism spectroscopy (SRCD) vacuum ultraviolet (VUV) structural biology protein secondary ... Synchrotron radiation circular dichroism (SRCD) spectroscopy: New beamlines and new applications in biology[J]. SPECTROSCOPY-AN ... Synchrotron radiation circular dichroism (SRCD) spectroscopy: New beamlines and new applications in biology. ... Miles, AJ,Hoffmann, SV,陶冶,Tao, Y,Janes, RW,&Wallace, BA.(2007).Synchrotron radiation circular dichroism (SRCD) spectroscopy: ...
Circular dichroism. HHV: Human herpesvirus. PQS: Putative quadruplex sequences. Declarations Acknowledgement. We would like to ...
Circular dichroism (CD) is then defined as Δk = k- - k+, and it follows the sign convention of natural optical activity. In the ... Magnetic circular dichroism (MCD) is the differential absorption of left and right circularly polarized (LCP and RCP) light, ... Upton, A. H. P.; Williamson, B. E. (1994). "Magnetic circular dichroism and absorption spectra of hexacyanoferrate(III) in a ... In this system, ω = 2 π ν {\displaystyle \omega =2\pi \nu } is the circular frequency, and n ~ {\displaystyle {\tilde {n}}} = n ...
circular dichroism (uncountable). *(chemistry, physics) the differential absorption of left-handed and right-handed circularly ... Retrieved from "https://en.wiktionary.org/w/index.php?title=circular_dichroism&oldid=44451934" ...
Optical rotatory dispersion Protein circular dichroism data bank Two-photon circular dichroism Vibrational circular dichroism P ... Molar ellipticity is circular dichroism corrected for concentration. Molar circular dichroism and molar ellipticity, [θ], are ... Optical rotary dispersion and circular dichroism share the same quantum information content. Linear dichroism Magnetic circular ... is the molar circular dichroism. This intrinsic property is what is usually meant by the circular dichroism of the substance. ...
Protein backbone circular dichroism Protein circular dichroism (CD) spectroscopy is usually divided into (1) far UV or backbone ... Linear dichroism and circular dichroism: a textbook on polarized spectroscopy. Cambridge: Royal Society of Chemistry; 2010. ... Rodger A, Nordén B. Circular dichroism and linear dichroism. Oxford: Oxford University Press; 1997.Google Scholar ... Single peptide bonds exhibit poly(pro)II ("random coil") circular dichroism spectra. J Am Chem Soc. 2005;127:9700-1.PubMed ...
"Vibrational Circular Dichroism of Polypeptides XII. Re-evaluation of the Fourier Transform Vibrational Circular Dichroism of ... acid Birefringence Circular dichroism Density functional theory DNA DNA structure IR spectroscopy Magnetic circular dichroism ... Vibrational circular dichroism (VCD) is a spectroscopic technique which detects differences in attenuation of left and right ... 1988). "Vibrational Circular Dichroism of Biopolymers". In E. D. Schmid; F. W. Schneider; F. Siebert. Spectroscopy of ...
Circular Dichroism. The Aviv Circular Dichroism Spectrometer, model 215, records CD as a function of wavelength, time, ...
Circular Dichroism (CD) analysis from SGS - meet regulatory requirements with class-leading CD spectroscopic analysis, alpha ... Life Sciences Circular Dichroism Analysis. Circular Dichroism (CD) analysis from SGS - meet regulatory requirements with class- ... Trusted circular dichroism from the leading provider. As the worlds leading provider of circular dichroism, we provide the ... Home › Life Sciences › Laboratory Services › Protein and Peptide Analysis › Circular Dichroism Analysis ...
... electronic circular dichroism), magnetic circular dichroisms (magnetic vibrational circular dichroism, x-ray magnetic circular ... dichroism), fluorescence detected circular dichroism, near-infrared circular dichroism, vibrational circular dichroism, Fourier ... transform infrared circular dichroism, high pressure liquid chromatography circular dichroism, stopped-flow circular dichroism ... This paper reviews the best known techniques using circular dichroism spectroscopy such as conventional circular dichroism (i.e ...
A stopped-flow circular dichroism instrument, with a total accessible wavelength range of 200 to 750 nanometers, has been ... Results obtained by following two such reactions at 222 nanometers represent direct monitoring by circular dichroism of rapid ...
... allows us to use light to investigate the structural properties of biological molecules such as ... Circular Dichroism Spectroscopy allows us to use light to investigate the structural properties of biological molecules such as ... Circular Dichroism Spectroscopy Biophysical Analysis Circular Dichroism Spectroscopy Circular Dichroism Spectroscopy Isothermal ...
Circular Dichroism. Circular Dichroism. Circular dichroism (CD) refers to the differential absorption of left and right ... Circular Polarization - Circular Dichroism. ... Circular dichroism (CD) is the differential absorption of left- and right- ... Circular Dichroism. ... Circular dichroism is one of the most general and basic tools to study protein folding ... Circular ... Other articles related to circular dichroism:. Circular Dichroism - Experimental Limitations. ... At the quantum mechanical ...
Johnson WC (1985) Circular dichroism and its empirical application to biopolymers. Methods Biochem Anal 31:61-163PubMed ... Kelly SM, Jess TJ, Price NC (2005) How to study proteins by circular dichroism. Biochim Biophys Acta 1751(2):119-139PubMed ... Circular dichroism Ligand binding Titration Binding constant UV denaturation Protein stability Data processing ... Brown EM, Groves ML (1985) Effect of temperature on the circular dichroism spectra of-β2-microglobulins. FEBS Lett 184(1):36-39 ...
Scharnagl, C.; Köst-Reyes, Eliana; Schneider, Siegfried; Köst, Hans-Peter; Scheer, Hugo (1983): Circular dichroism of ...
Accepted Manuscript: Circular dichroism in photoelectron images from aligned nitric oxide molecules ... The results demonstrate that circular dichroism is observed even when cylindrical symmetry is maintained, and serve as a ... We have used velocity map photoelectron imaging to study circular dichroism of the photoelectron angular distributions (PADs) ... reminder that dichroism is a general feature of the multiphoton ionization of atoms and molecules. Furthermore, the observed ...
Circular dichroism in ion yield is achieved by resonance-enhanced multiphoton ionization. The feasibility of circular dichroism ... Circular dichroism in ion yield has promising new potentials for chiral analysis. Our progress of its development is described ... Ab initio study of the one- and two-photon circular dichroism of R-(+)-3-methyl-cyclopentanone. Rizzo, Antonio; Na Lin; Ruud, ... The study explores in vitro by circular dichroism and mass spectrometry the effects of pH, Cu+2 ions and sheetbreakers on the ...
The magnetic circular dichroism and absorption spectra of Ta atoms isolated in an Ar matrix have been observed in the range 220 ... MAGNETIC CIRCULAR DICHROISM OF MATRIX-ISOLATED TANTALUM ATOMS. Please use this identifier to cite or link to this item: http:// ...
The Chirascan qCD (CD 250TM/AP) is used for characterization of biomolecules (secondary structure of proteins, polysaccharides and nucleic acid), determination of absolute configuration, and stereo chemical analysis. A primary use is in analysing the structure or conformation of large biological macromolecules, particularly proteins and DNA. The detector is able to measure UV to NIR range 165-900nm. ...
Circular dichroism (CD) spectroscopy is an optical technique that measures the difference in the absorption of left and right ... Maestre, M.F. Circular dichroism of DNA films: Reversibility studies. J. Mol. Biol 1970, 52, 543-556. [Google Scholar] ... Conformational Changes in DNA upon Ligand Binding Monitored by Circular Dichroism. Yu-Ming Chang 1, Cammy K.-M. Chen 1 and Ming ... Circular dichroism was also used to measure the interactions between hairpin DNA duplexes that contains regions of 2 bp G-tract ...
... Tengstedt, Carl Linköping University, ... X-ray magnetic circular dichroism measurements recorded at the V L2,3 edge confirmed room temperature magnetic ordering. A ...
... Bertucci C., Cimitan S ... Circular dichroism experiments supported this hypothesis. Furthermore, taxanes binding to the serum carrier was characterized ... drug paclitaxel and of several structural analogues has been characterized by bioaffinity chromatography and circular dichroism ...
Circular dichroism (CD) spectrometers market comprises an elaborate executive summary, which includes a market snapshot with ... circular dichroism spectrometers market was valued at approximately US$ 28.0 Mn in 2016 and is anticipated to register a CAGR ... DichroWeb and Protein Circular Dichroism Data Bank (PCDDB) are the two noteworthy reference information hotspots for circular ... The global circular dichroism spectrometers market is foreseen to expand at a CAGR of over 6.0% within the forecast period from ...
Differential scanning calorimetric, circular dichroism, and Fourier transform infrared spectroscopic characterization of the ... was studied by differential scanning calorimetry and Fourier transform infrared and circular dichroism spectroscopy. Our ...
  • A stopped-flow circular dichroism instrument, with a total accessible wavelength range of 200 to 750 nanometers, has been constructed and provides a spectroscopic method for kinetic investigations of a wide array of fast reactions in which optical activity changes in absorbing regions are involved. (sciencemag.org)
  • The global circular dichroism spectrometers market is foreseen to expand at a CAGR of over 6.0% within the forecast period from 2017 to 2025 to reach roughly near about US$51.0 mn by the end of 2025. (sbwire.com)
  • On the basis of region, in 2016, North America was accounted for maximum share of the global circular dichroism (CD) spectrometers market. (sbwire.com)
  • In this report, the global Circular Dichroism (CD) Spectrometers market is valued at USD XX million in 2017 and is expected to reach USD XX million by the end of 2025, growing at a CAGR of XX% between 2017 and 2025. (rnrmarketresearch.com)
  • We show that graphene plasmonic metasurfaces can create strong circular dichroism (CD) in mid-infrared due to the nanostructure's geometrical chirality and the plasmonic coupling between the elements in a chiral unit. (aps.org)
  • Chulhai, DV & Jensen, L 2015, ' Plasmonic circular dichroism of 310- and α-helix using a discrete interaction model/quantum mechanics method ', Journal of Physical Chemistry A , vol. 119, no. 21, pp. 5218-5223. (elsevier.com)
  • We present the technical implementation of far-UV circular dichroism in a nanosecond T-jump experiment and show that this experiment allows us to follow quantitatively the change in the helical fraction of a poly(glutamic acid) peptide during its thermal denaturation with 12 ns time resolution. (ebscohost.com)
  • Phosphorylation effect on the GSSS peptide conformation in water: Infrared, vibrational circular dichroism, and circular dichroism experiments and comparisons with molecular dynamics simulations. (ebscohost.com)
  • Vibrational circular dichroism spectrometer, a recent technique, is widely used to analyze peptide structures. (persistencemarketresearch.com)
  • Iron-Chromophore Circular Dichroism of [Fe]-Hydrogenase The Conformational Change Required for H2 Activation. (docme.ru)
  • Circular dichroism (CD) is a fast and relatively easy spectroscopic technique to study protein conformational behaviour in solution. (springer.com)
  • The study explores in vitro by circular dichroism and mass spectrometry the effects of pH, Cu+2 ions and sheetbreakers on the secondary structures and self-aggregation of b-amyloid peptides [A�43, A�42 and Abof Alzheimer's disease. (ebscohost.com)
  • In this way, the in-plane chiral structures (metasurfaces) can exhibit comparable differential absorption of the left and right circular polarizations of light to that of the graphene nanodisks assemblies. (aps.org)
  • X-ray crystallography is still the only routine method for determining the three-dimensional structures of biological macromolecules at high resolution (Kühlbrandt, 1988) which can be utilized for the comparison of the structures determined by circular dichroism (CD) deconvolution. (springer.com)
  • Protein secondary structures can also be determined experimentally from circular dichroism, and infrared spectroscopic data using empirical analysis methods. (biomedcentral.com)
  • Circular dichroism experiments supported this hypothesis. (uniprot.org)
  • We have used velocity map photoelectron imaging to study circular dichroism of the photoelectron angular distributions (PADs) of nitric oxide following two-color resonanceenhanced two-photon ionization via selected rotational levels of the A 2 Σ + , v' = 0 state. (osti.gov)
  • Ab initio study of the one- and two-photon circular dichroism of R-(+)-3-methyl-cyclopentanone. (ebscohost.com)
  • The 'Global and Southeast Asia Vibrational Circular Dichroism Spectrometer Industry, 2013-2023 Market Research Report' is a professional and in-depth study on the current state of the global Vibrational Circular Dichroism Spectrometer industry with a focus on the Southeast Asia market. (marketstudyreport.com)
  • How is circular dichroism used to study protein folding? (rocksurfers.org)
  • The circular dichroism of an optically active material is described by differential absorption of the left- and right-handed circularly polarized light. (techconnectworld.com)
  • JASCO has produced the highest quality circular dichroism instrumentation for over 50 years. (norlab.fi)
  • Magnetic circular dichroism (MCD) is the differential absorption of left and right circularly polarized (LCP and RCP) light, induced in a sample by a strong magnetic field oriented parallel to the direction of light propagation. (wikipedia.org)
  • Circular dichroism (CD) is dichroism involving circularly polarized light, i.e., the differential absorption of left- and right-handed light. (wikipedia.org)
  • Circular dichroism (CD) refers to the differential absorption of left and right circularly polarized light. (primidi.com)
  • Circular dichroism, with units of millidegrees, reflects detailed helical geometry and is defined as the difference between the absorption of left- and right-handed, circularly-polarised light measured as a function of wavelength (nm). (scielo.org.za)
  • Circular dichroism (CD) is the difference in the absorption of left-handed circularly polarized light and right-handed circularly polarized light and occurs when a molecule contains one or more chiral chromophores (light-absorbing groups). (biu.ac.il)
  • Circular dichroism showed complex results, in which AA and DTPA were strong modifiers of the percentages of the alpha-helical structure of HSA, while ribose affected the structure of HSA only at later time points. (mdpi.com)
  • Here, we present a novel kinetic assay that takes advantage of the loss of helical circular dichroic signals of insulin with IDE-dependent degradation. (portlandpress.com)
  • While helical and gyroid-based nanostructures exhibiting circular dichroism have been developed extensively to address this limitation, they are often restricted by the spectral inconsistency of their optical response. (edu.au)
  • This chimeric molecule forms a trimeric, highly α-helical, and very thermostable molecule, as determined by chemical crosslinking and circular dichroism. (pnas.org)
  • How have researchers confirmed the difference between a polyproline helical structure and a random coil using circular dichroism? (rocksurfers.org)
  • Since Δ ϵ {\displaystyle \Delta \epsilon } is a function of wavelength, a molar circular dichroism value ( Δ ϵ {\displaystyle \Delta \epsilon } ) must specify the wavelength at which it is valid. (wikipedia.org)
  • The Aviv Circular Dichroism Spectrometer, model 215, records CD as a function of wavelength, time, temperature, pH and concentration using a double monochromator containing two UV grade prisms as dispersing elements. (niu.edu)
  • Here we present the fabrication and characterization of quadruple-gyroid 4srs nanostructures exhibiting bio-inspired Bragg-mirror-like circular dichroism: a smooth and uniform band of circular dichroism reminiscent of the spectrum of a simple multilayer Bragg-mirror. (edu.au)
  • Furthermore, we demonstrate that the circular dichroism produced by 4srs nanostructures are robust to changes in incident angle and beam collimation, providing a new platform to create and engineer circular dichroism for functional circular polarization manipulation. (edu.au)
  • We offer you GLP/GMP-compliant circular dichroism analysis and class-leading spectroscopic profiling to help you meet your regulatory obligations. (sgs.com)
  • Why choose circular dichroism analysis from SGS? (sgs.com)
  • To find out more about our circular dichroism analysis, contact us today. (sgs.com)
  • Circular dichroism in ion yield has promising new potentials for chiral analysis. (ebscohost.com)
  • Circular dichroism analysis for proteinprotein interactions. (currentprotocols.com)
  • HOS analysis by circular dichroism is currently viewed as a 'Tier 3' CQA i.e. simple a graphical comparison. (photophysics.com)
  • Through the statistical analysis, the report depicts the global and Southeast Asia total market of Vibrational Circular Dichroism Spectrometer industry including capacity, production, production value, cost/profit, supply/demand and Southeast Asia import/export. (marketstudyreport.com)
  • In many practical applications of circular dichroism (CD), as discussed below, the measured CD is not simply an intrinsic property of the molecule, but rather depends on the molecular conformation. (wikipedia.org)
  • Progress to improve the statistical error and thus the lower limit of measurable circular dichroism is described. (ebscohost.com)
  • Whereas measurable dichroism occurs only in the region of absorption of the responsible chromophore, optical rotation extends well beyond this range, although with diminishing magnitude. (docme.ru)
  • The chiral periodic structure in the scale of optical wavelength gives rise to strong and characteristic circular dichroism responses at visible wavelengths. (techconnectworld.com)
  • Here we discuss how enantiomers may be differentiated by mass-selected photoelectron circular dichroism (MS-PECD) using an electron-ion coincidence imaging spectrometer. (chromatographyonline.com)
  • However, the simple nature of Bragg mirror reflection prevents their application to the control of important polarization states such as circular polarization. (edu.au)
  • Circular dichroism techniques: biomolecular and nanostructural analyses- a review. (nih.gov)
  • This intrinsic property is what is usually meant by the circular dichroism of the substance. (wikipedia.org)