Study of peptides inhibiting the angiotensin-converting enzyme of human seminal plasma

• Published in: Enzyme (Basel) Vol. 24; no. 6; p. 362
• Main Authors: Depierre, D, Bargetzi, J P, Roth, M
• Format: Journal Article
• Language: English
• Published: Switzerland 01.01.1979
• Subjects: Angiotensin II - metabolism; Angiotensin III - metabolism; Angiotensin-Converting Enzyme Inhibitors; Humans; Lung - enzymology; Male; Oligopeptides - pharmacology; Semen - enzymology; Teprotide - pharmacology
• DOI: 10.1159/000458691
• ISSN: 0013-9432

Several peptides were investigated for their inhibitory capacity against dipeptidyl carboxypeptidase (angiotensin-converting enzyme) from human seminal fluid. The strongest inhibitor was the nonapeptide SQ 20881. A marked inhibition was also shown by the compounds Phe-Ala-Pro and Boc-Phe-Ala-Pro, which behaved as competitive inhibitors. Among the peptides related to angiotensin, angiotensin III was the strongest inhibitor, followed by angiotensin II and the C-terminal hexapeptide of angiotensin II. The results indicate the dipeptidyl carboxypeptidase of human semen is very similar to pulmonary dipeptidyl carboxypeptidase in its susceptibility to peptide inhibitors. In view of these and other previously reported similarities, it is possible that both enzymes are identical.