Enriching C-terminal peptide from endopeptidase ArgC digest for protein C-terminal analysis.

This Letter describes a method for enriching C-terminal peptide of protein for C-terminal sequence analysis. This method employs endopeptidase ArgC digestion and C-terminal peptide enrichment using m-aminophenylboronic acid-agarose as an arginine-capture material. The selectively recovered C-terminal peptide incorporates no artificial derivatization. Therefore, the widely used functional groups (e.g. α-NH(2) and α-COOH) can be used for any necessary transformation. In this research, a TMPP mass tag was attached to the α-NH(2) group to clarify the amino acid sequence of the C-terminal peptide.