Evidence for a common selenolate intermediate in the glutathione peroxidase-like catalysis of α-(phenylselenenyl) ketones and diphenyl diselenide
✍ Scribed by Lars Engman; Claes Andersson; Ralf Morgenstern; Ian A. Cotgreave; Carl-Magnus Andersson; Anders Hallberg
- Book ID
- 104204313
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- French
- Weight
- 638 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
The glutathione peroxidase-like catalysis of a-(phenylselenenyl) ketones was investigated. Degradation studies demonstrated the rapid cleavage of the aliphatic carbon-selenium bond of a-(phenylselenenyl) ketones by glutathione at pH 6.9 in a methanolic phosphate buffer under argon. On treatment with excess glutathione under aerobic conditions, a-(phenylselenenyl) ketones, S-(phenylselenenyl)glutathione and diphenyl diselenide were all shown to give benzeneselenolate. This material was found to be oxidized by hydrogen peroxide considerably faster than a-(phenylseienenyl) ketones, S-@henylselenenyl)glutathione or diphenyl diselenide. A catalytic mechanism involving benzeneselenolate, benzeneselenenic acid and S-(phenylselenenyl)glutathione as cruical intermediates was proposed to account for the glutathione peroxidase-like catalysis of a-(phenylselenenyl) ketones and diphenyl diselenide.