MercaptoethanolSulfhydryl Compounds: Compounds containing the -SH radical.Molecular Weight: The sum of the weight of all the atoms in a molecule.Dithiothreitol: 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.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.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.Kinetics: The rate dynamics in chemical or physical systems.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)Sulfhydryl Reagents: 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.Chloromercuribenzoates: Chloride and mercury-containing derivatives of benzoic acid.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Agglutination Tests: Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.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.Brucella: A genus of gram-negative, aerobic bacteria that causes BRUCELLOSIS. Its cells are nonmotile coccobacilli and are animal parasites and pathogens. The bacterium is transmissible to humans through contact with infected dairy products or tissue.Dimercaprol: An anti-gas warfare agent that is effective against Lewisite (dichloro(2-chlorovinyl)arsine) and formerly known as British Anti-Lewisite or BAL. It acts as a chelating agent and is used in the treatment of arsenic, gold, and other heavy metal poisoning.Dithionitrobenzoic Acid: 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.Phenylmercury Compounds: Organic mercury compounds in which the mercury is attached to a phenyl group. Often used as fungicides and seed treatment agents.Cystine: 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.Hemagglutination Tests: Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)Iodoacetamide: An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Agglutinins: Substances, usually of biological origin, that cause cells or other organic particles to aggregate and stick to each other. They include those ANTIBODIES which cause aggregation or agglutination of particulate or insoluble ANTIGENS.Glutathione: 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.Zinostatin: An enediyne that alkylates DNA and RNA like MITOMYCIN does, so it is cytotoxic.Erythrocruorins: High molecular weight (1,500,000 to 3,000,000) hemoglobins found in the plasma of many polychete and oligochete annelid worms and various mollusks. They bind one mole of oxygen per heme and function as oxygen carriers.o-Phthalaldehyde: A reagent that forms fluorescent conjugation products with primary amines. It is used for the detection of many biogenic amines, peptides, and proteins in nanogram quantities in body fluids.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.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Isoelectric Point: The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.p-Chloromercuribenzoic Acid: An organic mercurial used as a sulfhydryl reagent.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.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).PhenanthrolinesEdetic Acid: A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.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.Brucellosis: Infection caused by bacteria of the genus BRUCELLA mainly involving the MONONUCLEAR PHAGOCYTE SYSTEM. This condition is characterized by fever, weakness, malaise, and weight loss.Hydroxymercuribenzoates: Hydroxylated benzoic acid derivatives that contain mercury. Some of these are used as sulfhydryl reagents in biochemical studies.Enzyme Reactivators: Compounds which restore enzymatic activity by removing an inhibitory group bound to the reactive site of the enzyme.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.Chromatography: Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.Immunoglobulin M: A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.Chromatography, DEAE-Cellulose: A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Iodoacetates: Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.Reducing Agents: 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)Drug Stability: The chemical and physical integrity of a pharmaceutical product.Isoelectric Focusing: Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.Chromatography, Ion Exchange: Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.Hemolytic Plaque Technique: A method to identify and enumerate cells that are synthesizing ANTIBODIES against ANTIGENS or HAPTENS conjugated to sheep RED BLOOD CELLS. The sheep red blood cells surrounding cells secreting antibody are lysed by added COMPLEMENT producing a clear zone of HEMOLYSIS. (From Illustrated Dictionary of Immunology, 3rd ed)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.Papain: A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC 3.4.22.2.Electrophoresis, Disc: Electrophoresis in which discontinuities in both the voltage and pH gradients are introduced by using buffers of different composition and pH in the different parts of the gel column. The term 'disc' was originally used as an abbreviation for 'discontinuous' referring to the buffers employed, and does not have anything to do with the shape of the separated zones.Immunodiffusion: Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.Cations, Divalent: Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.Hemagglutination: The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).Brucellosis, Bovine: A disease of cattle caused by bacteria of the genus BRUCELLA leading to abortion in late pregnancy. BRUCELLA ABORTUS is the primary infective agent.Indicators and Reagents: 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)Serum Globulins: All blood proteins except albumin ( = SERUM ALBUMIN, which is not a globulin) and FIBRINOGEN (which is not in the serum). The serum globulins are subdivided into ALPHA-GLOBULINS; BETA-GLOBULINS; and GAMMA-GLOBULINS on the basis of their electrophoretic mobilities. (From Dorland, 28th ed)gamma-Globulins: Serum globulins that migrate to the gamma region (most positively charged) upon ELECTROPHORESIS. At one time, gamma-globulins came to be used as a synonym for immunoglobulins since most immunoglobulins are gamma globulins and conversely most gamma globulins are immunoglobulins. But since some immunoglobulins exhibit an alpha or beta electrophoretic mobility, that usage is in decline.Macroglobulins: Serum globulins with high molecular weight. (Dorland, 28th ed)