Kate Halverson-Kolkind, David C Thorn, Martin Tovar-Ramirez, Eugene Shakhnovich, Larry David, Kirsten Lampi
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引用次数: 0
Abstract
The oxidation of cysteines in crystallins is a major age-related modification associated with cataract formation. The purpose of this research was to determine the susceptibility of γS-crystallin to glutathionylation-induced oxidation and disulfide bond formation. Recombinantly expressed wild-type human γS-crystallin and four cysteine-to-serine mutants were reduced and incubated for up to 2 days with oxidized glutathione. Following incubation and alkylation, the overall degree of glutathionylation and disulfide bond formation were determined by whole-mass measurement. Tryptic digests were also analyzed by LC-MS/MS to identify specific sites of S-glutathionylation and disulfide linkages. We determined that C22, C24, and C26 undergo glutathione-mediated disulfide interchange with each other, with C24 being most susceptible to oxidation and mixed disulfide formation. Our data suggest C24 is S-glutathionylated sequentially with C22 and C26 participating in disulfide exchange reactions, yielding a major species with a single glutathionylation at C24 and a disulfide between C22 and C26. The results imply that as glutathione levels are depleted in aged lenses, γS-crystallin undergoes stepwise oxidation reactions and disulfide shuffling, which may contribute towards its aggregation and cataract formation.
BiomoleculesBiochemistry, Genetics and Molecular Biology-Molecular Biology
CiteScore
9.40
自引率
3.60%
发文量
1640
审稿时长
18.28 days
期刊介绍:
Biomolecules (ISSN 2218-273X) is an international, peer-reviewed open access journal focusing on biogenic substances and their biological functions, structures, interactions with other molecules, and their microenvironment as well as biological systems. Biomolecules publishes reviews, regular research papers and short communications. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. There is no restriction on the length of the papers. The full experimental details must be provided so that the results can be reproduced.