title: Isolation and characterization of an enkephalin-degrading aminopeptidase from rat brain.
abstract: An enkephalin-degrading aminopeptidase from rat brain extracts has been purified to apparent homogeneity. This enzyme cleaves the N-terminal tyrosine from Leu-enkephalin and hydrolyzes some beta-naphthylamides and p-nitro-anilides of neutral, basic and aromatic, but not acidic, amino acids. The enzyme requires a free amino group on the substrate and has a neutral pH optimum. After dialysis against EDTA, the enzyme requires a divalent cation (Zn2+, Co2+ greater than Mn2% greater than Mg2+) for activity. The enzyme is inhibited by puromycin, o-phenanthroline, p-chloromercuribenzoate and EDTA, but not by puromycin, methylsulfonyl fluoride or a specific peptide inhibitor of leucine amino-peptidase. The aminopeptidase consists of two subunits and has a molecular weight of about 100 000.
mesh_terms: D000626:Aminopeptidases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004492:Edetic Acid / Q000494:pharmacology; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D051381:Rats; D013379:Substrate Specificity
chemical_list: D004723:Endorphins; D004745:Enkephalins; D004492:Edetic Acid; D000626:Aminopeptidases