PREPARATION OF CARBOXYL‐TERMINAL TRYPTIC PEPTIDES FROM PROTEINS BY CLEAVAGE AT ARGININE

Abstract
A method has been developed for selectively preparing the carboxyl‐terminal tryptic peptide of proteins by cleavage at arginyl residues. The succinylated protein is digested with trypsin and the peptides produced are maleylated. Maleylated peptides are then submitted to cation‐exchange chromatography in urea at low pH and ionic strength. Arginine‐containing peptides are retained by the resin. The carboxyl‐terminal peptide emerges unretarded and in pure form. This method has been applied to four proteins of known sequence. Yields as high as 88% have been obtained.