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Role of ultra-violet radiation, mercury and copper on the stability of dissolved glutathione in natural and artificial freshwater and saltwater
journal contribution
posted on 2023-05-20, 01:15 authored by Moingt, M, Bressac, M, Belanger, D, Amyot, MThe behavior and stability of dissolved reduced glutathione (GSH), an environmental antioxidant and metal transporter, is poorly known in natural waters. Glutathione oxidation rates were determined in both fresh- and brackish waters artificially submitted to different radiation wavebands. Photo-oxidation of GSH followed pseudo-first order kinetics, with half-lives ranging from 4 to 30 h in natural freshwater, and from 1.6 to 7 h in saltwater, with generally shorter persistence in UV-irradiated surface waters than in dark treatments. Chloride was shown to indirectly promote GSH photo-oxidation, probably through its role in the formation of radicals. The addition of Cu(II) to synthetic waters resulted in the rapid oxidation of GSH. The addition of Hg(II), a metal with strong affinity for thiols, protected GSH from oxidation by Cu(II) in the dark, but not under UV radiation. We conclude that UV-induced photo-oxidation is a key process altering the fate of GSH in natural waters. Also, the formation of stable GSH–Hg complexes could increase the bioavailability of Hg towards microorganisms in aquatic systems.
History
Publication title
ChemosphereVolume
80Issue
11Pagination
1314-1320ISSN
0045-6535Department/School
Institute for Marine and Antarctic StudiesPublisher
Pergamon-Elsevier Science LtdPlace of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England, Ox5 1GbRights statement
Copyright 2010 Elsevier Ltd.Repository Status
- Restricted