Aminopeptidase P, capable of hydrolyzing oligoproline, from bovine brain.

An aminopeptidase P, capable of hydrolyzing oligoproline, was isolated from the homogenate of bovine brain. The molecular mass of the enzyme was 140 kDa by gel filtration. The enzyme was activated by Mn2+ and inhibited by o-phenanthroline. The enzyme hydrolyzed substrates such as Pro-Pro-Pro-Pro, Pro-Pro-Pro, and Pro-Pro to proline, and cleaved N-terminal amino acids from peptides containing penultimate prolines such as bradykinin and neuropeptide Y.