An aminopeptidase activity from porcine kidney that hydrolyzes oxytocin and vasopressin: purification and partial characterization.
An aminopeptidase from porcine kidney, hydrolyzing oxytocin and vasopressin in vitro, was purified by chromatography on hydroxyapatite, DEAE-cellulose and nickel ion chelate gel and gel filtration on Sephadex G-100. The enzyme appeared to be a high molecular mass (M(r) 105,000) monomeric protein. It was sensitive to inhibition by metal chelator, o-phenanthroline. Cobalt ion and sulfhydryl activator, 2-mercaptoethanol, had activating effects, while p-chloromercuribenzoate, amino acids with large hydrophobic side chains, L-cystine and aminopeptidase inhibitors, bestatin and amastatin, had inhibitory effects on the enzyme activity. The enzyme hydrolyzed several aminoacyl p-nitroanilides, and had the highest specificity against S-benzyl-L-cysteine p-nitroanilide. The properties of the enzyme were distinct from those of well-characterized leucyl aminopeptidase (EC 3.4.11.1), membrane alanyl aminopeptidase (EC 3.4.11.2) and primate placental cystinyl aminopeptidase (EC 3.4.11.3).
Itoh
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Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Nagamatsu
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D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D007668:Kidney / Q000201:enzymology*; D010121:Oxytocin / Q000378:metabolism*; D013552:Swine; D014667:Vasopressins / Q000378:metabolism*
D014667:Vasopressins; D010121:Oxytocin; D000626:Aminopeptidases