A simple method to identify cysteine residues by isotopic labeling and iontrap mass spectrometry

A simple method was developed to facilitate the identification of cysteine- containing peptides based on S-carboxymethylation of cysteine residues with isotopically enriched bromoacetic acid. An ion trap mass spectrometer with high-resolution scan functionality allows identification of the unique iso topic distribution patterns specific to the modified peptides. Copyright (C ) 1999 John Wiley & Sons, Ltd.