One- and Two-Electron Oxidation of Reduced Glutathione by Peroxidases
The oxidation of glutathione by horseradish peroxidase or lactoperoxidase forms a thiyl free radical, as demonstrated with the spin-trapping ESR technique. Reactions of this thiyl free radical result in oxygen consumption, which is inhibited by the radical trap 5,5-dimethyl-l-pyrroline-Noxide. In contrast to L-cysteine oxidation, glutathione oxidation is highly hydrogen peroxide-dependent. The oxidation of glutathione by glutathione peroxidase forms GSSG without forming a thiyl radical intermediate except in the presence of the thiyl radical-generating horseradish peroxidase.
KeywordsHorseradish Peroxidase Glutathione Peroxidase Thiyl Radical Sulfinic Acid Superoxide Dismu
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- 6.L.S. Harman, D.K. Carver,J. Schreiber, and R.P. Mason, One- and two-electron oxidation of reduced glutathione by peroxidases, J. Biol. Chem. (in press).Google Scholar