Publication details
Electrochemical determination of glutathion and phytochelatins redox state
| Authors | |
|---|---|
| Year of publication | 2003 |
| Type | Article in Proceedings |
| Conference | XVII th International Symposium on Bioelectrochemistry and Bioenergetics |
| MU Faculty or unit | |
| Citation | |
| Field | Electrochemistry |
| Keywords | Glutathion; phytochelatins; reduced -SH; oxidized -S-S-; voltammetric methods; tributhylphosphine |
| Description | Glutathione (L-g-glutamyl-L-cysteinyl-glycine, GSH) occurs in different species of animals, plants, and procaryotes. It is a starting material for the synthesis of some peptides and proteins such as phytochelatins (PCs). Glutathione and phytochelatins play a key role in the detoxication of heavy metals in plant cells. In addition, GSH is a powerful antioxidant. Electrochemical methods have been employed in analysis of GSH and PCs and also in the study of oxidation and reduction of the sulphur group in cystein residues (reduced -SH/oxidized -S-S-). We used voltammetric methods in both differential pulse and square wave modes to study GSH and PCs redox states on a hanging mercury drop electrode. If the oxidation of reduced forms of the peptides (GSH and PCs) was started at -0.8 V (vs. Ag/AgCl/3M KCl), two reversible anodic peaks at -0.45 and -0.30 V were obtained. The first peak corresponds to the oxidation of the sulfhydryl group and its height is proportional to the amount of oxidized glutathione (GSSG) and PCs in a solution. Anodic signals were observed after aeration and/or addition of hydrogen peroxide to a solution containing reduced forms of peptides. The reducing agent tributyl phosphine showed the ability to preserve the reduction state of peptides. The study of the redox state of GSH and PCs is of great significance for the determination of redox cellular functions and the application of tributyl phosphine to preservation of reduced peptides is important in bioelectrochemical technology. |
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