Role of two chloride-binding sites in functioning of testicular angiotensin-converting enzyme.
Modeling the structure of the C-domain of bovine angiotensin-converting enzyme revealed two putative chloride-binding sites. The kinetic parameters, K(m) and k(cat), of hydrolysis of the substrate Cbz-Phe-His-Leu catalyzed by the testicular (C-domain) enzyme were determined over a wide range of chloride concentrations. Chloride anions were found to be enzyme activators at relatively low concentrations, but they inhibit enzymatic activity at high concentrations. A general scheme for the effect of chloride anions on activity of the C-domain of bovine angiotensin-converting enzyme accounting for binding the "activating" and "inhibiting" anions is suggested.
Moiseeva
N A
NA
Faculty of Chemistry, Lomonosov Moscow State University, Moscow, 119992, Russia. znatali@enzyme.chem.msu.ru
Binevski
P V
PV
Baskin
I I
II
Palyulin
V A
VA
Kost
O A
OA
D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001224:Aspartic Acid / Q000737:chemistry; D001665:Binding Sites; D002417:Cattle; D002712:Chlorides / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008239:Lysine / Q000737:chemistry; D008297:Male; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D013379:Substrate Specificity; D013737:Testis / Q000201:enzymology*
D000806:Angiotensin-Converting Enzyme Inhibitors; D002712:Chlorides; C477729:N-carbobenzoxy-phenylalanyl-histidyl-leucine; D009842:Oligopeptides; D001224:Aspartic Acid; D007703:Peptidyl-Dipeptidase A; D008239:Lysine