Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.

Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)

A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.

Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.

Chemical agents that react with SH groups. This is a chemically diverse group that is used for a variety of purposes. Among these are enzyme inhibition, enzyme reactivation or protection, and labelling.

A colorless, flammable, poisonous liquid, CS2. It is used as a solvent, and is a counterirritant and has local anesthetic properties but is not used as such. It is highly toxic with pronounced CNS, hematologic, and dermatologic effects.

A GLUTATHIONE dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized.

Compounds containing the -SH radical.

A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.

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.

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).

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.

A covalently linked dimeric nonessential amino acid formed by the oxidation of CYSTEINE. Two molecules of cysteine are joined together by a disulfide bridge to form cystine.

An enzyme that catalyzes the reduction of a protein-disulfide in the presence of glutathione, forming a protein-dithiol. Insulin is one of its substrates. EC 1.8.4.2.

Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.

Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.

International collective of humanitarian organizations led by volunteers and guided by its Congressional Charter and the Fundamental Principles of the International Red Cross Movement, to provide relief to victims of disaster and help people prevent, prepare for, and respond to emergencies.

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).

Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.

A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.

The rate dynamics in chemical or physical systems.

Materials that add an electron to an element or compound, that is, decrease the positiveness of its valence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

The parts of a macromolecule that directly participate in its specific combination with another molecule.

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.

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.

**Mercaptoethanol, also known as β-mercaptoethanol or BME, is an organosulfur compound with the formula HOCH2CH2SH, functionally serving as a reducing agent and a sulfhydryl group protector in biochemical and molecular biology applications.**

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

Proteins prepared by recombinant DNA technology.

Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.

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.

A sulfhydryl reagent that is widely used in experimental biochemical studies.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

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.

A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.

Narrow pieces of material impregnated or covered with a substance used to produce a chemical reaction. The strips are used in detecting, measuring, producing, etc., other substances. (From Dorland, 28th ed)

Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.

A radiation-protective agent that interferes with sulfhydryl enzymes. It may also protect against carbon tetrachloride liver damage.

Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.

Oxidoreductases with specificity for oxidation or reduction of SULFUR COMPOUNDS.

An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.

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.

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

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.

A family of thioltransferases that contain two active site CYSTEINE residues, which either form a disulfide (oxidized form) or a dithiol (reduced form). They function as an electron carrier in the GLUTHIONE-dependent synthesis of deoxyribonucleotides by RIBONUCLEOTIDE REDUCTASES and may play a role in the deglutathionylation of protein thiols. The oxidized forms of glutaredoxins are directly reduced by the GLUTATHIONE.

The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)

The process by which two molecules of the same chemical composition form a condensation product or polymer.

The sum of the weight of all the atoms in a molecule.

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.

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)

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.

'Allyl compounds' are organic substances that contain the allyl group (CH2=CH-CH2-) as a functional component, which can be found in various forms such as allyl alcohol, allyl chloride, and allyl esters.

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.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

A FLAVOPROTEIN enzyme that catalyzes the oxidation of THIOREDOXINS to thioredoxin disulfide in the presence of NADP+. It was formerly listed as EC 1.6.4.5

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)

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

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.

Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

A sulfhydryl reagent which oxidizes sulfhydryl groups to the disulfide form. It is a radiation-sensitizing agent of anoxic bacterial and mammalian cells.

Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Prepaid health and hospital insurance plan.

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.

Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.

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.

Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.

Established cell cultures that have the potential to propagate indefinitely.

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.

Proteins found in any species of bacterium.

Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.

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.

Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.

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).

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.

A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.

The space between the inner and outer membranes of a cell that is shared with the cell wall.

A subclass of IMIDES with the general structure of pyrrolidinedione. They are prepared by the distillation of ammonium succinate. They are sweet-tasting compounds that are used as chemical intermediates and plant growth stimulants.

The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.

Antibodies produced by a single clone of cells.

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.

Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.

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.

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.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

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.

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.

A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.

An enzyme that catalyzes the endonucleolytic cleavage of pancreatic ribonucleic acids to 3'-phosphomono- and oligonucleotides ending in cytidylic or uridylic acids with 2',3'-cyclic phosphate intermediates. EC 3.1.27.5.

A derivative of ACETIC ACID that contains one IODINE atom attached to its methyl group.

Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.

Elements of limited time intervals, contributing to particular results or situations.

The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).

Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

Organic salts or esters of methanesulfonic acid.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

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.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

Phenanthrolines are a class of heterocyclic compounds containing two aromatic hydrocarbon rings fused with a third ring consisting of nitrogen atoms, which have been used in the development of various pharmaceutical and chemical research applications, including as antibacterial, antifungal, and antiviral agents, enzyme inhibitors, and chelators.

Proteins obtained from ESCHERICHIA COLI.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.

The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.

Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.

The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.

The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.

A cytotoxic sulfhydryl reagent that inhibits several subcellular metabolic systems and is used as a tool in cellular physiology.

Measurement of the intensity and quality of fluorescence.

Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.

Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.

Presence of warmth or heat or a temperature notably higher than an accustomed norm.

Serine proteinase inhibitors which inhibit trypsin. They may be endogenous or exogenous compounds.

Peptide neurotoxins from the marine fish-hunting snails of the genus CONUS. They contain 13 to 29 amino acids which are strongly basic and are highly cross-linked by disulfide bonds. There are three types of conotoxins, omega-, alpha-, and mu-. OMEGA-CONOTOXINS inhibit voltage-activated entry of calcium into the presynaptic membrane and therefore the release of ACETYLCHOLINE. Alpha-conotoxins inhibit the postsynaptic acetylcholine receptor. Mu-conotoxins prevent the generation of muscle action potentials. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)

CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.

A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.

Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.

Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.

A continuous circle of peptide bonds, typically of 2-3 dozen AMINO ACIDS, so there is no free N- or C-terminus. They are further characterized by six conserved CYSTEINE residues that form CYSTINE KNOT MOTIFS.

Benzoic acid esters or salts substituted with one or more iodine atoms.

A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.

The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.

A family of ubiquitously-expressed peroxidases that play a role in the reduction of a broad spectrum of PEROXIDES like HYDROGEN PEROXIDE; LIPID PEROXIDES and peroxinitrite. They are found in a wide range of organisms, such as BACTERIA; PLANTS; and MAMMALS. The enzyme requires the presence of a thiol-containing intermediate such as THIOREDOXIN as a reducing cofactor.

Proteins found in the PERIPLASM of organisms with cell walls.

Transport proteins that carry specific substances in the blood or across cell membranes.

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)

The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.

The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.

Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.

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)

Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.

Maleimides are a class of chemically reactive compounds containing a maleimide functional group, which can undergo addition reactions with nucleophiles such as thiols, making them useful for the formation of covalent bonds in various bioconjugation and material synthesis applications.

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)

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

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.

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)

Organic or inorganic compounds that contain the -N3 group.

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)

Method of analyzing chemicals using automation.

Sites on an antigen that interact with specific antibodies.

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.

A single-chain polypeptide derived from bovine tissues consisting of 58 amino-acid residues. It is an inhibitor of proteolytic enzymes including CHYMOTRYPSIN; KALLIKREIN; PLASMIN; and TRYPSIN. It is used in the treatment of HEMORRHAGE associated with raised plasma concentrations of plasmin. It is also used to reduce blood loss and transfusion requirements in patients at high risk of major blood loss during and following open heart surgery with EXTRACORPOREAL CIRCULATION. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)

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.

An organic mercurial used as a sulfhydryl reagent.

The process of cleaving a chemical compound by the addition of a molecule of water.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

A reagent that is highly selective for the modification of arginyl residues. It is used to selectively inhibit various enzymes and acts as an energy transfer inhibitor in photophosphorylation.

Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)

Oxy acids of sulfur with the general formula RSOH, where R is an alkyl or aryl group such as CH3. They are often encountered as esters and halides. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.

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).

A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.

The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

Incorporation of biotinyl groups into molecules.

The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.

An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.

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.

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.

Esters of the hypothetical imidic acids. They react with amines or amino acids to form amidines and are therefore used to modify protein structures and as cross-linking agents.

Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.

Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.

The relationship between the dose of an administered drug and the response of the organism to the drug.

The chemical and physical integrity of a pharmaceutical product.

Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).

A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)

Peroxidases are enzymes that catalyze the reduction of hydrogen peroxide to water, while oxidizing various organic and inorganic compounds, playing crucial roles in diverse biological processes including stress response, immune defense, and biosynthetic reactions.

A complex of cyclic peptide antibiotics produced by the Tracy-I strain of Bacillus subtilis. The commercial preparation is a mixture of at least nine bacitracins with bacitracin A as the major constituent. It is used topically to treat open infections such as infected eczema and infected dermal ulcers. (From Goodman and Gilman, The Pharmacological Basis of Therapeutics, 8th ed, p1140)

Any method used for determining the location of and relative distances between genes on a chromosome.

A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.

Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)

Genetic loci associated with a QUANTITATIVE TRAIT.

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.

A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.

A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.

The characteristic three-dimensional shape of a molecule.

Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).

The methyl imidoester of suberic acid used to produce cross links in proteins. Each end of the imidoester will react with an amino group in the protein molecule to form an amidine.

Chloride and mercury-containing derivatives of benzoic acid.

A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.

CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)

A major protein fraction of milk obtained from the WHEY.

Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).

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.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.

An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.

A series of steps taken in order to conduct research.

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.

The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.

The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.