Muraceins - Muramyl peptides produced by Nocardia orientalis as angiotensin-converting enzyme inhibitors I. Taxonomy, fermentation and biological properties.

Abstract

Three muraceins, a family of muramyl peptides, were isolated from N. orientalis as inhibitors of angiotensin-converting enzyme (ACE). Muracein A, the most potent inhibitor, inhibited ACE competitively with a Ki of 1.5 .mu.M. Liver alcohol dehydrogenase and carboxypeptidase A, two other .alpha.-containing enzymes, were not inhibited at 150 .mu.M. Inhibition of ACE could not be reversed by divalent cations. [ACE is recognized as a pharmacologically important target in the treatment of hypertension.].