Issue 9, 2011

Glutathione: mechanism and kinetics of its non-enzymatic defense action against free radicals

Abstract

Glutathione, which is the most abundant cytosolic thiol, plays important roles in the non-enzymatic antioxidant defence system. Its free radical scavenging activity towards radicals of different nature (·OH, ·OOH, ·OCH3, ·OOCH3, ·OOCHCH2 and ·OOCCl3) have been studied in aqueous solution, using the Density Functional Theory. It was found that the rate constants range from 2.02 × 104 M−1s−1 to diffusion limit (7.68 × 109 M−1s−1). Therefore it can be stated that glutathione is an excellent free radical scavenger, able of efficiently scavenging a wide variety of free radicals. It reacts exclusively by H transfer, and with the exception of its reaction with ·OH there is only one important channel of reaction, yielding to the S-centered radical. For the reaction with ·OH, on the other hand, a wide product distribution is expected, which explains the formation of C-centered radicals experimentally observed. Glutathione was found to be exceptionally good as a OOH radical scavenger, comparable to 2-propenesulfenic acid. This has been explained based on the strong H bonding interactions found in the transition states, which involves the carboxylate moiety. Therefore this might have implications for other biological systems where this group is present.

Graphical abstract: Glutathione: mechanism and kinetics of its non-enzymatic defense action against free radicals

Article information

Article type
Paper
Submitted
17 Jul 2011
Accepted
23 Aug 2011
First published
25 Okt 2011

RSC Adv., 2011,1, 1763-1771

Glutathione: mechanism and kinetics of its non-enzymatic defense action against free radicals

A. Galano and J. R. Alvarez-Idaboy, RSC Adv., 2011, 1, 1763 DOI: 10.1039/C1RA00474C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements