Size-based Peptide Sorting: Gel Mobility Study of Cysteinyl Tryptic Peptides

摘要

Mass spectrometric data of peptides, in combination with sample processing information (such as enzymes used and the type of cysteine modification), allow the automated search of proteins against genome/proteome databases. Additional constraints on peptide properties increase the specificity of the search and reduce false-positive identification of proteins. The numbers of specific amino acid residues and isoelectric points of peptides, for example, have shown great values in such endeavors. Herein, we present a method for correlating cysteinyl peptide size and accurate number of cysteines with the gel mobility of the peptides that are modified by size-labels. These relations can potentially serve as valuable constraints for mass spectrometry-based proteomic analysis.