Molecular Conformation: The characteristic three-dimensional shape of a molecule.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).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.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)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).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.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.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.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (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.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.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)Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.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.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)Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.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.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)Kinetics: The rate dynamics in chemical or physical systems.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.Polymorphism, Single-Stranded Conformational: Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.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.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.Molecular Dynamics Simulation: A computer simulation developed to study the motion of molecules over a period of time.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)Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.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)Cornea: The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)Electrophoresis, Gel, Two-Dimensional: Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.Dimethyl Sulfoxide: A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.Cell Adhesion: Adherence of cells to surfaces or to other cells.Corneal Dystrophies, Hereditary: Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.Ethylenebis(dithiocarbamates): A class of thiocarbamate derivatives whose salts possess fungicidal activity.Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.PhotochemistryThiocarbamates: Carbamates in which the -CO- group has been replaced by a -CS- group.Air Ionization: The dissociation of molecules in the air into positive and negative ions under the influence of an electric field.Galaxies: Large aggregates of CELESTIAL STARS; COSMIC DUST; and gas. (From McGraw Hill Dictionary of Scientific and Technical Terms, 6th ed)Cycloserine: Antibiotic substance produced by Streptomyces garyphalus.Alanine Racemase: A pyridoxal-phosphate protein that reversibly catalyzes the conversion of L-alanine to D-alanine. EC 5.1.1.1.Serine C-Palmitoyltransferase: A key enzyme in SPHINGOLIPIDS biosynthesis, this enzyme catalyzes the pyridoxal-5'-phosphate-dependent condensation of L-SERINE and PALMITOYL COENZYME A to 3-dehydro-D-sphinganine. The enzyme consists of two different subunits.Ceramides: Members of the class of neutral glycosphingolipids. They are the basic units of SPHINGOLIPIDS. They are sphingoids attached via their amino groups to a long chain fatty acyl group. They abnormally accumulate in FABRY DISEASE.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.Ficain: A sulfhydryl proteinase with cysteine at the active site from ficus latex. Preferential cleavage is at tyrosine and phenylalanine residues. EC 3.4.22.3.Histamine: An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.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)Copyright: It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)Catalogs, Publishers'Editorial Policies: The guidelines and policy statements set forth by the editor(s) or editorial board of a publication.Publishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.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.

Molecular dynamics studies of U1A-RNA complexes. (1/8682)

The U1A protein binds to a hairpin RNA and an internal-loop RNA with picomolar affinities. To probe the molecular basis of U1A binding, we performed state-of-the-art nanosecond molecular dynamics simulations on both complexes. The good agreement with experimental structures supports the protocols used in the simulations. We compare the dynamics, hydrogen-bonding occupancies, and interfacial flexibility of both complexes and also describe a rigid-body motion in the U1A-internal loop complex that is not observed in the U1A-hairpin simulation. We relate these observations to experimental mutational studies and highlight their significance in U1A binding affinity and specificity.  (+info)

Gangliosides of human kidney. (2/8682)

Five gangliosides isolated from human kidney have been characterized. The two main fractions were shown to be typical extraneural gangliosides in having lactose as their neutral carbohydrate moiety. Their structures were identified as: AcNeu(alpha2-3)Gal(beta1-4)Glc(beta1-1)Cer and AcNeu(alpha2-8)AcNeu(alpha2-3)Gal(beta1-4)Glc(beta1-1)Cer. The two main hexosamine-containing gangliosides are structurally related to human blood group substances of glycosphingolipid nature. The following structures are postulated: AcNeu(alpha2-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc(beta1-1)Cer and AcNeu(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)Gal(beta1-4)Glc(beta1-1) Cer. The third hexosamine-containing ganglioside belongs to a different series of glycolipids and was shown to have the structure of a major ganglioside of human brain: AcNeu(alpha2-3)Gal(beta1-3)GalNAc(beta1-4)[AcNeu(alpha2-3)]Gal(beta1-4)Glc(beta1- 1)Cer. The fatty acid structure of different gangliosides was shown to resemble that of neutral glycolipids of human kidney with the nonhydroxy acids C16:0, C22:0, and C24:0 as major components.  (+info)

Carbon 13 NMR study of nonenzymatic reactions of pyridoxal 5'-phosphate with selected amino acids and of related reactions. (3/8682)

Carbon 13 nuclear magnetic resonance spectroscopy has been used to monitor the nonenzymatic reactions of pyridoxal 5'-phosphate with glycine, alanine, valine, serine, and with several other model compounds. Isotopically enriched amino acids were employed so that low concentrations could be utilized while still allowing relatively rapid acquisition of spectral data. The results for alanine and serine are particularly noteworthy in that alanine is deaminated to pyruvate and pyruvate is aminated to alanine, but contrary to the enzymatic reactions of various serine dehydratases wherein serine is converted to pyruvate, the nonenzymatic reaction utilizing serine results in hydroxypruvate rather than pyruvate formation. In the reverse reaction, hydroxypyruvate is aminated to serine but very inefficiently relative to the amination of pyruvate to alanine. The experimental results have been formulated into a proposed reaction mechanism for deamination of amino acids by pyridoxal-P.  (+info)

Voltage sensors in domains III and IV, but not I and II, are immobilized by Na+ channel fast inactivation. (4/8682)

Using site-directed fluorescent labeling, we examined conformational changes in the S4 segment of each domain of the human skeletal muscle sodium channel (hSkM1). The fluorescence signals from S4 segments in domains I and II follow activation and are unaffected as fast inactivation settles. In contrast, the fluorescence signals from S4 segments in domains III and IV show kinetic components during activation and deactivation that correlate with fast inactivation and charge immobilization. These results indicate that in hSkM1, the S4 segments in domains III and IV are responsible for voltage-sensitive conformational changes linked to fast inactivation and are immobilized by fast inactivation, while the S4 segments in domains I and II are unaffected by fast inactivation.  (+info)

Quantitative study of polymer conformation and dynamics by single-particle tracking. (5/8682)

We present a new method for analyzing the dynamics of conformational fluctuations of individual flexible polymer molecules. In single-particle tracking (SPT), one end of the polymer molecule is tethered to an immobile substratum. A microsphere attached to the other end serves as an optical marker. The conformational fluctuations of the polymer molecule can be measured by optical microscopy via the motion of the microsphere. The bead-and-spring theory for polymer dynamics is further developed to account for the microsphere, and together the measurement and the theory yield quantitative information about molecular conformations and dynamics under nonperturbing conditions. Applying the method to measurements carried out on DNA molecules provides information complementary to recent studies of single DNA molecules under extensional force. Combining high precision measurements with the theoretical analysis presented here creates a powerful tool for studying conformational dynamics of biological and synthetic macromolecules at the single-molecule level.  (+info)

The structure of human parathyroid hormone-related protein(1-34) in near-physiological solution. (6/8682)

Parathyroid hormone-related protein plays a major role in the pathogenesis of humoral hypercalcemia of malignancy. Under normal physiological conditions, parathyroid hormone-related protein is produced in a wide variety of tissues and acts in an autocrine or paracrine fashion. Parathyroid hormone-related protein and parathyroid hormone bind to and activate the same G-protein-coupled receptor. Here we present the structure of the biologically active NH2-terminal domain of human parathyroid hormone-related protein(1-34) in near-physiological solution in the absence of crowding reagents as determined by two-dimensional proton magnetic resonance spectroscopy. An improved strategy for structure calculation revealed the presence of two helices, His-5-Leu-8 and Gln-16-Leu-27, connected by a flexible linker. The parathyroid hormone-related protein(1-34) structure and the structure of human parathyroid hormone(1-37) as well as human parathyroid hormone(1-34) are highly similar, except for the well defined turn, His-14-Ser-17, present in parathyroid hormone. Thus, the similarity of the binding affinities of parathyroid hormone and parathyroid hormone-related protein to their common receptor may be based on their structural similarity.  (+info)

Apolipoprotein A-I charge and conformation regulate the clearance of reconstituted high density lipoprotein in vivo. (7/8682)

While low apolipoprotein A-I (apoA-I) levels are primarily associated with increased high density lipoprotein (HDL) fractional catabolic rate (FCR), the factors that regulate the clearance of HDL from the plasma are unclear. In this study, the effect of lipid composition of reconstituted HDL particles (LpA-I) on their rate of clearance from rabbit plasma has been investigated. Sonicated LpA-I containing 1 to 2 molecules of purified human apoA-I and 5 to 120 molecules of palmitoyl-oleoyl phosphatidylcholine (POPC) exhibit similar charge and plasma FCR to that for lipid free apoA-I, 2.8 pools/day. Inclusion of 1 molecule of apoA-II to an LpA-I complex increases the FCR to 3.5 pools/day, a value similar to that observed for exchanged-labeled HDL3. In contrast, addition of 40 molecules of triglyceride, diglyceride, or cholesteryl ester to a sonicated LpA-I containing 120 moles of POPC and 2 molecules of apoA-I increases the negative charge of the particle and reduces the FCR to 1.8 pools/day. Discoidal LpA-I are the most positively charged lipoprotein particles and also have the fastest clearance rates, 4.5 pools/day. Immunochemical characterization of the different LpA-I particles shows that the exposure of an epitope at residues 98 to 121 of the apoA-I molecule is associated with an increased negative particle charge and a slower clearance from the plasma. We conclude that the charge and conformation of apoA-I are sensitive to the lipid composition of LpA-I and play a central role in regulating the clearance of these lipoproteins from plasma. conformation regulate the clearance of reconstituted high density lipoprotein in vivo.  (+info)

Application of distance geometry to 3D visualization of sequence relationships. (8/8682)

SUMMARY: We describe the application of distance geometry methods to the three-dimensional visualization of sequence relationships, with examples for mumps virus SH gene cDNA and prion protein sequences. Sequence-sequence distance measures may be obtained from either a multiple sequence alignment or from sets of pairwise alignments. AVAILABILITY: C/Perl code and HTML/VRML files from http://www.nibsc.ac.uk/dg3dseq/  (+info)

  • Since the GpA transmembrane segment (and, presumably, the V 18 segment) is helical in the lipid-embedded form of the protein [ 8 , 9 ], this suggests that a hydrophobic segment with low helix potential in water may enter the translocon as an extended stretch of polypeptide and will only fold into a helical conformation upon lateral exit from the translocation channel into the lipid bilayer. (biomedcentral.com)
  • Molecular conformation is any spatial arrangement of the atoms in a molecule which can be interconverted by rotations about formally single bonds. (nature.com)
  • In distinction to Extended Hückel Theory which predicts as the most stable conformation of free zwitterionic GABA a totally extended form, PCILO and SCF ab initio studies show that the intrinsically preferred conformation of the isolated molecule is a highly folded one, resulting from strong interactions between the two charged ends. (springer.com)
  • This is a particularly difficult problem when the drug is a flexible molecule with many energetically accessible conformations. (njit.edu)
  • The side chain of the Pro residue of molecule A is in the flattened C γ-endo conformation while the pyrrolidine ring in miolecule B adopts the well-known C γ -exo conformation. (ias.ac.in)
  • Experimental techniques are able to estimate distances between pairs of atoms of a given molecule, and the problem becomes the one of identifying the three-dimensional conformation of the molecule, i.e. the positions of all its atoms. (wikipedia.org)
  • abstract = "OBJECTIVE: To assess the molecular mechanism of rifampin (RMP) resistance in clinical strains of Mycobacterium tuberculosis. (elsevier.com)
  • Crystallographic and NMR analyses of Lys11-linked diubiquitin reveal that Lys11-linked chains adopt compact conformations in which Ile44 is solvent exposed. (nature.com)
  • The primary effect of the solvent is the appearance of a barrier on the order k B T, not present in the ideal gas, between the free energy basins corresponding to compact and extended chain conformations, and destabilization of the most extended conformations. (princeton.edu)
  • Ab initio studies have been carried out on glycyl-L-alanine zwitterion using the basis sets 6-31 + g(d), 6-31++g(d,p) and 6-311g(d,p) to obtain its stable molecular conformation both in the gas phase and in solvent media of dielectric constants \varepsilon = 2.2 and 78.0 corresponding to carbon tetrachloride and water, respectively. (iisc.ac.in)
  • A computational strategy to simulate two-dimensional electronic spectra (2DES) is introduced, which allows us to analyse ground state dynamics and to sample and measure different conformations attained by flexible molecular systems in solution. (escholarship.org)
  • The interaction of a dielectric medium has only a marginal effect on the molecular conformation and vibrational spectra. (iisc.ac.in)
  • In the title compound, C(26)H(32)N(2), the cyclo-hexane and piperazine rings each adopt a chair conformation.Both phenyl rings and the two propen-3-yl residues are in equatorial positions.The absolute configuration was assigned with reference to the starting material. (nih.gov)
  • We have previously shown that the conformation of nascent polypeptide chains in transit through the ribosome-translocon complex can be probed by measuring the number of residues required to span the distance between the ribosomal P-site and the lumenally disposed active site of the oligosaccharyl transferase enzyme (J. Biol. (biomedcentral.com)
  • Chem 271: 6241-6244).Using this approach, we now show that model segments composed of residues with strong helix-forming properties in water (Ala, Leu) have a more compact conformation in the ribosome-translocon channel than model segments composed of residues with weak helix-forming potential (Val, Pro). (biomedcentral.com)
  • L 17 V, A 17 V, V 18 , P 18 ) in locations that are either within the ribosome or the translocon in the truncated nascent chain we find that d P-O values tend to fall near either 65 or 70 residues, and we equate these two values with extended and helical conformations of the model stretches, respectively. (biomedcentral.com)
  • These chemical shifts predominately reflect the local conformations of the peptides and are largely independent of the identity of neighboring residues. (factbites.com)
  • In this particular case, one wants to generate alternate conformations for the side chains of residues 1 and 7. (yale.edu)
  • This chapter introduces two basic examples of direct electrical control of biomolecular conformation, namely, voltage-gated ion channels in excised, surface immobilized, biological membranes, and antibodies of the IgG type, immobilized on an electrode surface. (oreilly.com)
  • Zhu L, Cheng X, Su W, Zhao J, Zhou C. Molecular Insights into Sequence Distributions and Conformation-Dependent Properties of High-Phenyl Polysiloxanes. (mdpi.com)
  • Role of DNA conformation & energetic insights in Msx-1-DNA recognition as revealed by molecular dynamics studies on specific and nonspecific complexes. (osdd.net)
  • These results provide insights into both the molecular mechanisms that govern biofilm formation in Crenarchaea and the functionality of the Lrs14-like proteins, an archaea-specific class of transcriptional regulators. (scoop.it)
  • Molecular dynamics can be useful for assessing the energetic stability of proteins and identifying available conformations and, therefore, analyzing available binding pockets. (cresset-group.com)
  • This study shows that wild-type proteins do not always sample the conformations available to disease-relevant mutant proteins and that comprehensive drug testing of patient-derived cells can identify unpredictable, clinically significant drug-repositioning opportunities. (nih.gov)
  • Zoonosis outbreaks, such as the H7N9 outbreak, underscore the need to better understand the molecular organization of viral immunogens, such as recombinant influenza virus hemagglutinin (HA) proteins, used in influenza virus subunit vaccines in order to optimize vaccine efficacy. (pubmedcentralcanada.ca)
  • In this field, the main interest is on proteins, because discovering their three-dimensional conformation allows us to get clues about the function they are able to perform. (wikipedia.org)
  • It is necessary to study the spatial relationship of these molecular recognition features in order to determine the pharmacophore of the drug. (njit.edu)
  • In both cases, the action of an applied electric field results in the modulation of protein conformation mediated by the response of positively charged amino acids (lysine, arginine) moving in response to an electric field. (oreilly.com)
  • Ye, Q, Woo, MW & Selomulya, C 2019, ' Modification of molecular conformation of spray-dried whey protein microparticles improving digestibility and release characteristics ', Food Chemistry , vol. 280, pp. 255-261. (monash.edu)
  • Ferguson, AL , Debenedetti, PG & Panagiotopoulos, AZ 2009, ' Solubility and molecular conformations of n-Alkane chains in water ', Journal of Physical Chemistry B , vol. 113, no. 18, pp. 6405-6414. (princeton.edu)
  • The chemical symbols example "Design elements - Conformations" was created using the ConceptDraw PRO software extended with the Chemistry solution from the Science and Education area of ConceptDraw Solution Park. (conceptdraw.com)
  • Organic Crystal Engineering provides reviews of topics in organic crystal engineering that will be of interest to all researchers in molecular solid-state chemistry. (wiley.com)
  • Experimental data accumulated to date made it possible to establish a relationship between the [E.sub.values of these polymers and their molecular conformation and mechanical properties (5). (thefreelibrary.com)
  • For instance, polymers having a fully extended planer zigzag conformation such as polyethylene (PE) and polyvinyl alcohol (PVA) exhibit high [E.sub. values (PE: 235 GPa, PVA: 250 GPa). (thefreelibrary.com)
  • In these polymers, the deformation modes of a molecular chain are both bond stretching and bond angle bending which have high force constants. (thefreelibrary.com)
  • In contrast, polymers with helical or contracted conformation such as isotactic polypropylene (PP) and polyoxymethyelne (POM) possess relatively lower [E.sub.(PP: 42 GPa, and POM: 54 GPa). (thefreelibrary.com)
  • Molecular properties arise from the contribution of many conformers, and in the case of a drug binding a target, may be due mainly to a few distinct members. (arxiv.org)
  • Although an equilibrium exists between the 1C4 and 2S0 conformers (ratio 60:40) of the 2-O-sulfo-α-L-iduronate ring (IdoA2S) in the free state, FGFR2 selects only the unique twisted-boat 2S0 conformation of this IdoA2S residue. (csic.es)
  • Other torsion angles such as θ 2 1 = 86(1)°, χ 2 = −5(2)°, = 131(1)°, and χ 12 = −16(2)° are interesting to define the backbone conformation together with the dehydro-Leu side chain as a conformation similar to that of the β-bend type II. (ias.ac.in)
  • Compounds (II) and (III) are isostructural [dihedral angle between the aromatic rings = 8.31 (5)° in (II) and 5.34 (15)° in (III)] and differ from (I) in showing a near-syn conformation for the Nm-C-C=N linker [torsion angles for (II) and (III) = 17.64 (18) and 8.7 (5)°, respectively], which allows for the occurrence of a short intra-molecular C-H...N contact. (elsevier.com)
  • Detect Single Nucleotide Sequence Changes with Mx4000 Molecular Beacon,,,Allelic Discrimination Kits ( Allelic discrim. (bio-medicine.org)
  • Stratagenes Mx4000 molecular beacon allelic discrimination kits include the following components: a mixture of two allele-specific molecular beacons with an exact sequence match to each of the two target sequence variants, three genotype-specific DNA controls corresponding to the homozygotes and the heterozygote of the two sequence variants, target-specific PCR primers, and an optimized PCR buffer. (bio-medicine.org)
  • By using two different molecular beacons in each PCR reaction, three possible allelic combinations (genotypes) of two sequence variants can be distinguished simultaneously by the type of fluorescence detected: TET fluorescence indicates homozygosity for the wild-type allele, FAM fluorescence indicates homozygosity for the mutant allele, and both TET and FAM fluorescence together indicates heterozygosity ( Figure 2 ). (bio-medicine.org)
  • Multinuclear n.m.r. spectroscopy has been used to confirm the identify of inositol 1,4,5-trisphosphate and to deduce its molecular conformation as having five equatorial and one axial ring substituents. (biochemj.org)
  • The results demonstrate the importance of integrin extension in rolling, and suggest that rolling and firm adhesion are mediated by extended conformations of alpha(L)beta(2) that differ in the affinity of the alpha(L) I domain for ICAM-1. (nih.gov)
  • Chemical shifts of amino acid carbons in the solid state in a beta-sheet conformation differ by as much as 8 ppm from those in an alpha-helix (Saito, 1986). (factbites.com)
  • 2 This thermal instability of mismatched hybrids increases the specificity of molecular beacons, thus enabling them to distinguish targets that differ by a few or only a single nucleotide. (bio-medicine.org)
  • In the title compound, C(26)H(32)N(2), the cyclo-hexane and piperazine rings each adopt a chair conformation. (nih.gov)
  • Molecular conformation of the title compound with the atomic numbering scheme and displacement ellipsoids drawn at the 30% probability level. (nih.gov)