Sulfhydryl Compounds: Compounds containing the -SH radical.Tiopronin: Sulfhydryl acylated derivative of GLYCINE.beta-Aminoethyl Isothiourea: A radiation-protective agent that can inhibit DNA damage by binding to the DNA. It also increases the susceptibility of blood cells to complement-mediated lysis.Cysteamine: A mercaptoethylamine compound that is endogenously derived from the COENZYME A degradative pathway. The fact that cysteamine is readily transported into LYSOSOMES where it reacts with CYSTINE to form cysteine-cysteamine disulfide and CYSTEINE has led to its use in CYSTINE DEPLETING AGENTS for the treatment of CYSTINOSIS.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.MercaptoethanolCysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.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.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)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).Kinetics: The rate dynamics in chemical or physical systems.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.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.Chloromercuribenzoates: Chloride and mercury-containing derivatives of benzoic acid.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Iodoacetamide: An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.Mercuribenzoates: Mercury-containing benzoic acid derivatives.p-Chloromercuribenzoic Acid: An organic mercurial used as a sulfhydryl reagent.