ENZYMIC SYNTHESIS OF OLIGOPETIDE - VI. THE MECHANISTIC FEATURES OF PEPSIN-CATALYSED PEPTIDE SYNTHESIS

Article abstract of DOI:10.1016/S0040-4020(01)97630-6

The dipeptide Z-Phe-Phe-OBzl and tripeptide Z-Phe-Phe-Phe-OBzl were synthesized by pepsin catalysis from the incubation of Z-Phe and Phe-OBzl in the reaction solution.The yield ratio of two peptides in relation to reaction time was investigated by HPLC.Another example: The tripeptide Z-Phe-Leu-Phe-OBzl and tetrapeptide Z-Phe-Leu-Phe-Phe-OBzl were also synthesized concurrently from Z-Phe-Leu and Phe-OBzl by pepsin catalysis.These results may have important implication for the transpeptidation of pepsin.But, according to the report of Pellegrini and Luisi, the dipeptide, Z-Ph-Phe-OBzl, synthesized by pepsin catalysis was not contaminated with the tripeptide,Z-Phe-Phe-Phe-OBzl, and the yield was high.In order to investigate the discrepancies between our observation and those reported by Pellegrini and Luisi, a mechanism by which pepsin synthesizes the dipeptide, Z-Phe-Phe-OBzl, and tripeptide, Z-Phe-Phe-Phe-OBzl, is proposed and supporting data demonstrated by HPLC analysis.