Inhibition of Prolyl Endopeptidase by Synthetic Peptide Fragments of Human β-Casein

Abstract

It has been suggested that peptide inhibitors of prolyl endopeptidase (PEP) may act as anti-amnestic agents. In the hope of finding PEP inhibitors in milk proteins, we synthesized a total of 37 human β-casein peptide fragments containing proline residues. It was found that the peptides with PEP inhibition activity in vitro were located in the region of amino acid residues 49-59 of human β-casein. The most potent inhibitor was Ile-Tyr-Pro-Phe-Val-Glu-Pro-Ile (IC50 = 8 μM). © 1991, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.