Publisher: John Wiley & Sons Inc
E-ISSN: 1096-9888|50|12|1358-1366
ISSN: 1076-5174
Source: JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Vol.50, Iss.12, 2015-12, pp. : 1358-1366
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
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.
Related content
By Borisov R. Zaikin V. Vas’kovskii B. Sklyarov L.
Russian Chemical Bulletin, Vol. 55, Iss. 12, 2006-12 ,pp. :