Inactivation of bradykinin by placental peptidases.
Normal human placental eluate (0.15 M NaCl) has very high capacity for inactivating synthetic bradykinin (its specific activity is 20--50 times higher than that of normal human serum). In chromatography on DEAE-Sephadex A 50, several fractions with bradykinin-inactivating capacity were recovered. On Cbo-Phe-Arg synthetic substrate, one fraction with kininase activity was identified as carboxypeptidase N. This is not identical with serum (pregnancy) carboxypeptidase N and does not therefore pass into the blood stream. The properties of other fractions with kininase activity were studied. Aminopeptidase activity degrading L-lysine-p-nitranilide and L-arginine-beta-naphthylamide was separate from kininase activity.
D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D001920:Bradykinin; D002852:Chromatography, Ion Exchange; D005260:Female; D006801:Humans; D010920:Placenta / Q000201:enzymology*; D051381:Rats
D000626:Aminopeptidases; D001920:Bradykinin