biostudies-literaturePaulech JLundbeck Foundation609-20https://www.ebi.ac.uk/biostudies/studies/S-EPMC4349981biostudies-literatureUnknown14(3)Cysteine (Cys) oxidation is a crucial post-translational modification (PTM) associated with redox signaling and oxidative stress. As Cys is highly reactive to oxidants it forms a range of post-translational modifications, some that are biologically reversible (e.g. disulfides, Cys sulfenic acid) and others (Cys sulfinic [Cys-SO2H] and sulfonic [Cys-SO3H] acids) that are considered "irreversible." We developed an enrichment method to isolate Cys-SO2H/SO3H-containing peptides from complex tissue lysates that is compatible with tandem mass spectrometry (MS/MS). The acidity of these post-translational modification (pKa Cys-SO3H < 0) creates a unique charge distribution when localized on tryptic peptides at acidic pH that can be utilized for their purification. The method is based on electrostaMolecular & cellular proteomics : MCPGlobal analysis of myocardial peptides containing cysteines with irreversible sulfinic and sulfonic acid post-translational modifications.PMC4349981R83-2011-8143Engholm-Keller KPaulech JLiddy KAWhite MYCordwell SJfalseGlobal analysis of myocardial peptides containing cysteines with irreversible sulfinic and sulfonic acid post-translational modifications.Cysteine (Cys) oxidation is a crucial post-translational modification (PTM) associated with redox signaling and oxidative stress. As Cys is highly reactive to oxidants it forms a range of post-translational modifications, some that are biologically reversible (e.g. disulfides, Cys sulfenic acid) and others (Cys sulfinic [Cys-SO2H] and sulfonic [Cys-SO3H] acids) that are considered "irreversible." We developed an enrichment method to isolate Cys-SO2H/SO3H-containing peptides from complex tissue lysates that is compatible with tandem mass spectrometry (MS/MS). The acidity of these post-translational modification (pKa Cys-SO3H < 0) creates a unique charge distribution when localized on tryptic peptides at acidic pH that can be utilized for their purification. The method is based on electrosta2015-01-01T00:00:00Z2015 Mar2026-04-16T21:17:00.439Z2019-03-27T01:47:34ZS-EPMC43499812556150210.1074/mcp.M114.04434710.1074/mcp.m114.044347