Sulfonium ion derivatization, isobaric stable isotope labeling and data dependent CID- and ETD-MS/MS for enhanced phosphopeptide quantitation, identification and phosphorylation site characterization.

ABSTRACT: An amine specific peptide derivatization strategy involving the use of novel isobaric stable isotope encoded 'fixed charge' sulfonium ion reagents, coupled with an analysis strategy employing capillary HPLC, ESI-MS, and automated data dependent ion trap CID-MS/MS, -MS(3), and/or ETD-MS/MS, has been developed for the improved quantitative analysis of protein phosphorylation, and for identification and characterization of their site(s) of modification. Derivatization of 50 synthetic phosphopeptides with S,S'-dimethylthiobutanoylhydroxysuccinimide ester iodide (DMBNHS), followed by analysis using capillary HPLC-ESI-MS, yielded an average 2.5-fold increase in ionization efficiencies and a significant increase in the presence and/or abundance of higher charge state precursor ions compared to th

SUBMITTER: Lu Y 

PROVIDER: S-EPMC4228788 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature