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Redox-changes associated with the glutathione-dependent ability of the Cu(II)–GSSG complex to generate superoxide
- Source :
-
Bioorganic & Medicinal Chemistry . May2012, Vol. 20 Issue 9, p2869-2876. 8p. - Publication Year :
- 2012
-
Abstract
- Abstract: The intracellularly-occurring Cu(I)–glutathione complex (Cu(I)–[GSH]2) has the ability to reduce molecular oxygen into superoxide. Removal of such radicals leads to the irreversible conversion of Cu(I)–[GSH]2 into the redox-inactive Cu(II)–GSSG complex. The present study addressed the potential of reduced glutathione, ascorbate and superoxide to reductively regenerate Cu(I)–[GSH]2 from Cu(II)–GSSG, and investigated the redox changes involved in such process. Results show that: (i) among the three tested reductants, only GSH is able to reduce the Cu(II) bound to GSSG; (ii) during the reduction of Cu(II)–GSSG, a Cu(I)–GSSG intermediate would be formed (supported here by Cu(I) and GSSG recovery data and by NMR studies); (iii) when GSH is present in a molar excess equal or greater than 1:3, the reduction of Cu(II)–GSSG into Cu(I)–[GSH]2 is quantitative and complete. Under such conditions, the Cu(II)–GSSG complex acquires a superoxide-generating capacity which is identical to that seen with the Cu(I)–[GSH]2 complex. Within cells, the concentrations of GSH are at least 2- to 3-fold order of magnitude higher than those expected for the Cu(II)–GSSG complex. Thus, we postulate that the interaction between GSH and Cu(II)–GSSG could be seen as a potential mechanism to regenerate continuously the Cu(I)–[GSH]2 complex and thereby affect the ability of the latter to generate superoxide. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09680896
- Volume :
- 20
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- Bioorganic & Medicinal Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 74553850
- Full Text :
- https://doi.org/10.1016/j.bmc.2012.03.027