Enzymic Cleavage of Post-Proline Peptide Bonds: Degradation of Arginine-Vasopressin and Angiotensin II 1

Abstract

Summary

A partially purified enzyme from human uterine tissue was found to cleave peptides specifically at the carboxyl side of proline residues when arginine-vasopressin, oxytocin, and Ile⁵-angiotensin II were tested as proline-containing substrates. The enzyme has a pH optimum of 7.4; its activity is not affected by Mn²⁺ or Mg²⁺ (10^-6 to 10^-3 M).

The authors thank Dr. T. D. Kerenyi for his active participation and interest in this work. The technical help of Mrs. I. Mintz was appreciated.