A kininase and a kinin-converting enzyme: two distinct alpha aminoacyl peptide hydrolases from bovine lung.
Two closely related but different aminopeptidases from bovine lung have been isolated and characterized. The first aminopeptidase, which removes the N-terminal arginine residue from L-arginyl-L-prolyl-L-proline, bradykinin, and des-[Arg9]-bradykinin, has kininase activity; it has a pH optimum of 8.0, is stimulated by Mn2+, and its molecular weight in dilute buffers is slightly greater than 240,000 daltons. The second aminopeptidase, which converts kallidin to bradykinin, has kinin-converting activity; it has a pH optimum of 6.8, is stimulated by Co2+, and its molecular weight in dilute buffers is 250,000 daltons. The kinin-converting enzyme is blocked from action when the N-terminal penultimate residue is proline.
D000626:Aminopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008168:Lung / Q000201:enzymology*; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D013379:Substrate Specificity
D008345:Manganese; D000626:Aminopeptidases