Characterization of dehydroascorbate‐mediated modification of glutaredoxin by mass spectrometry
Ascorbate is as a potent antioxidant in vivo protecting the organism against oxidative stress. In this process, ascorbate is oxidized in two steps to dehydroascorbate (DHA), which if not efficiently reduced back to ascorbate decomposes irreversibly to a complex mixture of products. We demonstrate th...
Saved in:
Published in | Journal of mass spectrometry. Vol. 50; no. 12; pp. 1358 - 1366 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Wiley
01.12.2015
Blackwell Publishing Ltd Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Ascorbate is as a potent antioxidant in vivo protecting the organism against oxidative stress. In this process, ascorbate is oxidized in two steps to dehydroascorbate (DHA), which if not efficiently reduced back to ascorbate decomposes irreversibly to a complex mixture of products. We demonstrate that a component of this mixture specifically reacts with the thiol group of cysteine residues at physiological pH to give a protein adduct involving the addition of a 5‐carbon fragment of DHA (+112 Da). Incubations of glutaredoxin‐1 expressed in Escherichia coli and dehydroascorbate revealed abundant adducts of +112, +224 and +336 Da due to the addition of one, two and three conjugation products of DHA, respectively. ESI–MS of carbamidomethylated glutaredoxin‐1 before incubation with DHA, deuterium exchange together with tandem mass spectrometry analysis and LC–ESIMS/MS of modified peptides confirmed structure and sites of modification in the protein. Modification of protein thiols by a DHA‐derived product can be involved in oxidative stress‐mediated cellular toxicity. Copyright © 2015 John Wiley & Sons, Ltd. |
---|---|
Bibliography: | http://dx.doi.org/10.1002/jms.3706 Natural Sciences and Engineering Research Council of Canada ArticleID:JMS3706 ark:/67375/WNG-ZJ6LC018-H istex:6065EDDC9A7EEC28534CF41FF95264451C73ACF1 Supporting information ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1076-5174 1096-9888 |
DOI: | 10.1002/jms.3706 |