title: Angiotensin-converting enzyme in human prostate.
abstract: The activity of angiotensin-converting enzyme in human prostate was measured by spectrophotometric method using Hippuryl-L-histidyl-L-leucine (Hip-His-Leu) as substrate. Benign hypertrophic prostate had significantly higher concentration of angiotensin-converting enzyme (1.99 +/- 0.36 (S.E.M.) units/g of tissue, n = 13) than normal prostate (0.44 +/- 0.1 units/g of tissue, n = 5) (p less than 0.01). More than 80% of the enzyme activity occurred in soluble fraction of normal and hypertrophied prostates. Human prostatic angiotensin-converting enzyme, partially purified from benign hypertrophic prostates, had an apparent molecular weight of 290,000 and pI of 4.1. Optimum pH of the enzyme with KM value of 1.0 mmol/l was 7.8 in 0.1 mmol/l borate/sodium/carbonate buffer. The enzyme was competitively inhibited by captopril (Ki, 1.8 nmol/l).
mesh_terms: D002712:Chlorides / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D007526:Isoelectric Point; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D007703:Peptidyl-Dipeptidase A / Q000032:analysis* / Q000096:biosynthesis; D011467:Prostate / Q000201:enzymology*; D011470:Prostatic Hyperplasia / Q000201:enzymology
chemical_list: D002712:Chlorides; D007703:Peptidyl-Dipeptidase A