Harnessing Redox Cross-Reactivity To Profile Distinct Cysteine Modifications.

ABSTRACT: Cysteine S-nitrosation and S-sulfination are naturally occurring post-translational modifications (PTMs) on proteins induced by physiological signals and redox stress. Here we demonstrate that sulfinic acids and nitrosothiols react to form a stable thiosulfonate bond, and leverage this reactivity using sulfinate-linked probes to enrich and annotate hundreds of endogenous S-nitrosated proteins. In physiological buffers, sulfinic acids do not react with iodoacetamide or disulfides, enabling selective alkylation of free thiols and site-specific analysis of S-nitrosation. In parallel, S-nitrosothiol-linked probes enable enrichment and detection of endogenous S-sulfinated proteins, confirming that a single sulfinic acid can react with a nitrosothiol to form a thiosulfonate linkage. Using this a

SUBMITTER: Majmudar JD 

PROVIDER: S-EPMC4883004 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature