TY - JOUR TI - ESR investigation of the reactions of glutathione, cysteine and penicillamine thiyl radicals: competitive formation of RSOcenter dot, Rcenter dot, RSSRcenter dot-. , and RSScenter dot AB - The reactions of cysteine, glutathione and penicillamine thiyl radicals with oxygen and their parent thiols in frozen solutions have been elucidated with e.s.r. The major sulfur radicals observed are: (1) thiyl radicals, RS center dot; (2) disulfide radical anions, RSSR anion radicals; (3) perthiyl radicals, RSS center dot and upon introduction of oxygen; (4) sulfinyl radicals, RSO center dot, where R represents the remainder of the cysteine, glutathione or penicillamine moiety. The radical product observed depends on pH, concentration of thiol, and presence or absence of molecular oxygen. The sulfinyl radical is a ubiquitous intermediate, peroxyl radical attack on thiols may lead to sulfinyl radicals. The authors elaborate the observed reaction sequences that lead to sulfinyl radicals and, using /sup 17/O isotopic substitution studies, demonstrate the oxygen atom in sulfinyl radicals originates from dissolved molecular oxygen. The glutathione radical is found to abstract hydrogen from the ..cap alpha..-carbon position on the cysteine residue of glutathione to form a carbon-centred radical. AU - "Becker, David" AU - "Swarts, Steven" AU - "Champagne, Mark" AU - "Sevilla, M D" KW - "63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT." KW - "THIYL RADICALS" KW - "ELECTRON SPIN RESONANCE" KW - "AQUEOUS SOLUTIONS" KW - "CYSTEINE" KW - "GLUTATHIONE" KW - "OXYGEN" KW - "PENICILLAMINE" KW - "PH VALUE" KW - "RADICALS" KW - "RESPONSE MODIFYING FACTORS" KW - "THIOLS" KW - "AMINO ACIDS" KW - "CARBOXYLIC ACIDS" KW - "CHELATING AGENTS" KW - "DISPERSIONS" KW - "DRUGS" KW - "ELEMENTS" KW - "MAGNETIC RESONANCE" KW - "MIXTURES" KW - "NONMETALS" KW - "ORGANIC ACIDS" KW - "ORGANIC COMPOUNDS" KW - "ORGANIC SULFUR COMPOUNDS" KW - "PEPTIDES" KW - "POLYPEPTIDES" KW - "PROTEINS" KW - "RADIOPROTECTIVE SUBSTANCES" KW - "RESONANCE" KW - "SOLUTIONS" KW - "560120* - Radiation Effects on Biochemicals, Cells, & Tissue Culture" DO - https://doi.org/ UR - PB - CY - United Kingdom PY - 1988 DA - 1988-05-01 LA - English J2 - [] VL - 53:5 C1 - Oakland Univ., Rochester, MI (USA). Dept. of Chemistry C2 - C3 - C4 - C5 - L3 - Journal Name: Int. J. Radiat. Biol. Relat. Stud. Phys., Chem. Med.; (United Kingdom); Journal Volume: 53:5 ER -