Oxidation of glutathione

Sastre, J., Asensi, M., Gasco, E., Pallardo, F.V., Ferrero, J.A., Furukawa, T. and Vina, J. (1992). Exhaustive physical exercise causes oxidation of glutathione status in blood prevention by antioxidant administration. Am. J. Physiol. 263, R992-R995. 

Kachur, A., Koch, C., and Biaglow, J., Mechanism of copper-catalyzed oxidation of glutathione, Free Radic Res, 28 (3), 259-269, 1998. 

Nasr et failed to observe a change in the ratio of NADPH to NADP in the tracheal epithelium of rats exposed to ozone at 33 ppm for an hour. This apparently negative in vivo finding is not surprising, inasmuch as NADP will be rapidly reduced back to NADPH if ozone does not disrupt the structural integrity of pyridine nucleotides. In addition, de novo thesis of pyridine nucleotides may also occur. The intracellular ratio of reduced to oxidized pyridine nucleotides is under tine cellular control, in that the oxidation of NADPH or NADH results in the stimulation of enzymatic activity, which restores the initial ratio. In the case of NADPH, its oxidation increases the activity of the hexose monophosphate shunt this also occurs after the oxidation of glutathione. The rel-... 

Zhang H, SquadritoGL, Uppu RM, Lemercier J-N,Cueto R, Pryor WA (1997) Inhibition of peroxynitrite-mediated oxidation of glutathione by carbon dioxide. Arch Biochem Biophys 339 183-189... 

Ellison DH, Salmon GA, Wilkinson F (1972) Nanosecond pulse radiolysis of methanolic and aqueous solutions of readily oxidizable solutes. Proc R Soc Lond A 328 23-36 Erben-Russ M, Bors W, Saran M (1987) Reactions of linoleic acid peroxyl radicals with phenolic antioxidants a pulse radiolysis study. Int J Radiat Biol 52 393-412 Eriksen TE, Fransson G (1988) Radical-induced oxidation of glutathione in alkaline aqueous solution. Radiat Phys Chem 32 163-167... 

Wefers, H., and Stes, H. (1983). Oxidation of glutathione by the superoxide radical to the distilfide and the sulfonate yielding singlet oxygen. Eirr. /. Biackem. 137, 29-36. 

The overall reaction is oxidation of glutathione at the expense of hydrogen peroxide, organic hydroperoxides, and fatty acid hydroperoxides, respectively, according to the following reaction ... 

TBHP accelerates oxidation of glutathione and decreases the metabolism of sodium hexabarbitol in rat livers and is a strong oxidation agent. 

Sastre J, Asensi M, Cased E, Ferrero JA, Furukawa T,Vina J (1992) Exhaustive physical exercise causes and oxidation of glutathione status in blood. Prevention by antioxidant administration. Am J Physiol 263 R992-R995... 

Copper deficiency is reported to cause a 2-fold increase in the level of lipid hydroperoxides in rat liver mitochondria and microsomes along with decreases in Cu-Zn SOD [696]. Cytosolic and mitochondrial glutathione peroxidase and catalase activities were also decreased [696]. Increased lipid peroxidation was suggested to be due to the accumulation of hydrogen peroxide rather than superoxide. Alternatively, some lipid peroxidation may be due to the formation of singlet oxygen [444] and its oxidation of glutathione to its disulphide and/or oxidation of Fe(II)catalase to the inactive Fe(III) form. 

Since many of the radical or non-radical reactions in cells may lead to thiol oxidation to the disulfide, i.e., the oxidation of glutathione to form GSSG, the regenerative reaction of rereduction to GSH catalyzed by GSSG reductase can become pivotal in antioxidant defense (1) ... 

FIG U RE 3.2 The gamma glutamyl cycle and its linkages with taurine metabolism, transamination, and oxidation of glutathione. 

C2oH32N60i2S2] " NHi V H0-C-CH CH2 CH2-C-NH Fast flow oxidation of glutathione / 2.0065 OlBonl... 

The iron(II) catalyzed oxidation of glutathione (GSH) has been studied kinetically. The reaction takes place via a red intermediate, whose rapid formation can be observed upon exposure of the Fe(II)/GSH complex to oxygen. It has been identified as compound 2. The kinetic results are consistent with the following mechanism shown in Scheme 1 [50]. 

Plants have an enzyme system linking the oxidation of,glutathione to the reduction of dehydroascorbic acid. A similar enzyme may occur in animal tissues, although in this case a facile non-en matic reaction could possibly account for the observed activity. The plant eni me provides a... 

Hendley, D. D., and E. E. Conn Enzymic reduction and oxidation of glutathione by illuminated chloroplasts. Arch. Biochem. Biophys. 46, 454 (1953). 

These results are in agreement with the recognized [6] electron-mediating behaviour of Amavadine for the oxidation of glutathione and other biological thiols (cysteine, cysteine methyl ester and penicillamine). 

Z. Dische You mentioned the presence in cells of nonenzymatic catalysts which can oxidize GSH and which at physiological pH seem to be more efficient than the corresponding enzymes. I think there is reason to wonder whether those nonenzymatic catalysts are not mainly responsible for the oxidation of glutathione. By fixation on certain surfaces these catalysts can be organized. I wonder whether enzymes which oxidize GSH are not of lesser biological importance than the nonenzymatic catalysts. 

E. S. Barron Ascorbic acid cannot protect the oxidation of glutathione because its oxidation-reduction potential is much more positive than that of glutathione. 

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