Novel Cleavable Probe for Cysteinyl-Peptide Enrichment and LC-MS/MS Analysis in Complex Protein Mixtures

摘要

A mild base-cleavable Cys-reactive biotin probe (IBB) was synthesized. Cys-containg peptide IBB conjugates are stable in low pH buffer and are easily hydrolyzed under mild ly basic conditions (pH > 7 or ambic). Cys-containing peptide and non Cys-containing peptides were separated efficiently through strepvadin capture followed by ambic cleavage. IBB Cys-containing peptide enrichment dramatically increase protein identifications in RKO cell lysates. IBB Cys-containing peptide enrichment improves low abundance protein identification in yeast proteomes.