title: Partial purification and characterization of four aminopeptidases from the soluble fraction of human placenta.
abstract: Four aminopeptidases hydrolysing amino acid-beta-naphthylamides were partially purified from human placental soluble fraction. Separation of the activities, Con-pools I, II1, II2 and III, have not been previously reported. They had apparent molecular weights of 80,000, 100,000, 210,000, and 120,000, respectively. Con-pool II2 seemed to be a glycoprotein. Con-pools I and III were activated by sulphydryl modifiers and inhibited by p-chloromercuribenzoate (p-CMB), properties which indicate their dependence on thiol-groups. Con-pool II1 hydrolysed only arginine- and lysine-beta-naphthylamides. It was inhibited by bestatin and p-CMB. Its special characteristic was activation by monovalent anions, notably chloride ions. These results suggest that Con-pool II1 is aminopeptidase B.
mesh_terms: D000626:Aminopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D002458:Cell Fractionation; D002712:Chlorides / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002845:Chromatography; D006801:Humans; D010920:Placenta / Q000201:enzymology*; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: D002712:Chlorides; D002729:Chloromercuribenzoates; D013439:Sulfhydryl Reagents; D000626:Aminopeptidases; C019721:aminopeptidase B