Tripeptidyl Carboxypeptidase Activity of Angiotensin-Converting Enzyme in Human Tissues of the Urogenital Tract

The tripeptidyl carboxypeptidase activity of angiotensin-converting enzyme (EC 3.4.15.1) has been determined in several human tissues of the urogenital tract. Benzoyl-glycyl-L-seryl-L-prolyl-L-phenylalanine was used as substrate. The cleaved benzoyl-glycine was measured by means of high-performance liquid chromatography. Results obtained showed a high enzymatic activity for seminal plasma, vesicula seminalis and benign prostatic hyperplasia. Normal prostate and in particular prostatic adenocarcinoma have low enzymatic activity. The activity of the enzyme is sensitive to inhibition by the angiotensin-converting enzyme inhibitor captopril.