Demonstration and characterization of angiotensin-converting enzyme in human pituitary tissue.
High activity of angiotensin-converting enzyme was demonstrated in human pituitary tissue. This activity required the presence of chloride ion and was almost completely inhibited by a specific converting enzyme inhibitor captopril (10 nM), indicating that the activity measured is indeed angiotensin-converting enzyme. The specific activity of the enzyme was 1.68 +/- 1.20 nmol hippuric acid generated mg of protein-1 min-1 (mean +/- SD, for 11 specimens). The biochemical features of the enzyme were closely related to the well-characterized human lung converting enzyme, such as molecular weight (290,000), optimum pH (8.0-8.5), the presence of glycoprotein residues, and dependence on chloride ion concentration. These results provide definitive evidence for the presence of angiotensin-converting enzyme in human pituitary tissue.
D002712:Chlorides / Q000494:pharmacology; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology; D017830:Octoxynol; D007703:Peptidyl-Dipeptidase A / Q000032:analysis*; D010902:Pituitary Gland / Q000201:enzymology*; D011092:Polyethylene Glycols; D013696:Temperature
D002712:Chlorides; D011092:Polyethylene Glycols; D017830:Octoxynol; D007703:Peptidyl-Dipeptidase A