title: Decrease in accessible thiols as an index of oxidative damage to membrane proteins.
abstract: The effect of several oxidative agents (hydrogen peroxide, tert-butyl hydroperoxide, menadione, AAPH, peroxynitrite and ionizing radiation) on the ratio of weakly to strongly immobilized residues of erythrocyte membrane-bound maleimide-tempo spin label (h(w)/h(s) ratio) was studied in order to test the hypothesis that a decrease in the h(w)/h(s) ratio may be a general index of oxidative damage to membrane proteins. Most of the agents studied decreased though H2O2 almost did not affect and ionizing radiation increased the h(w)/h(s) ratio. In parallel, the ratio of DTNB accessible/DTNB inaccessible membrane protein-SH groups was determined from membrane-SH group measurements with the Ellman reagent in the absence and in the presence of sodium dodecyl sulfate. This ratio decreased in all cases studied and seems to be a more universal and easy to measure parameter to describe the oxidative damage to membrane proteins.
authors.affiliation: Department of Molecular Biophysics, University of Lodź, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Soszyński
authors.forename: G
authors.initials: G
authors.lastname: Bartosz
mesh_terms: D000328:Adult; D000578:Amidines / Q000494:pharmacology; D003497:Cyclic N-Oxides; D004228:Dithionitrobenzoic Acid / Q000378:metabolism / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D005720:Gamma Rays; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D009566:Nitrates / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D010545:Peroxides / Q000494:pharmacology; D013113:Spin Labels; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D014812:Vitamin K / Q000494:pharmacology; D020122:tert-Butylhydroperoxide
chemical_list: D000578:Amidines; D003497:Cyclic N-Oxides; D008565:Membrane Proteins; D009566:Nitrates; D016877:Oxidants; D010545:Peroxides; D013113:Spin Labels; D013438:Sulfhydryl Compounds; D014812:Vitamin K; C017480:4-maleimido-2,2,6,6-tetramethylpiperidinooxyl; C039642:peroxynitric acid; C046728:2,2'-azobis(2-amidinopropane); D020122:tert-Butylhydroperoxide; D004228:Dithionitrobenzoic Acid; D006861:Hydrogen Peroxide