Action of carboxypeptidase W on oligopeptides containing carboxy-terminally amidated peptides
作者:Hironori Umetsu、Kiyoshi Hishinuma、Hitoshi Wake、Michio Takeuchi、Eiji Ichishima
DOI:10.1016/s0031-9422(97)00074-5
日期:1997.7
Carboxypeptidase W sequentially liberated amino acids from the carboxy-terminus of angiotensin I, bradykinin, delta sleep-inducing peptide and neurotensin, indicating that the sequential hydrolysis of peptides was limited by the occurrence of intermediates with the structure -Gly-X (X = L-amino acid), -Pro-X, -X-Gly and -X-Pro. The enzyme had carboxyamidase and/or amidase activities for the carboxy-terminally amidated peptides and then carboxypeptidase activity. Carboxyamidase activity of the enzyme for the carboxy-terminally amidated peptides tested was much lower than carboxypeptidase activity for Z-Glu-Tyr (Z = benzyloxycarbonyl). The enzyme essentially acted as a carboxyamidase for the long carboxy-terminally amidated peptides; an amidase became dominant for the substrates in the presence of a hydrophobic amino acid in the penultimate (P-1) or P-1 positions, especially the P-1 position, corresponding with the S-1 and S-2 sites of the enzyme. (C) 1997 Elsevier Science Ltd. All rights reserved.