New chloride-activated aminopeptidase from human erythrocytes.
A new Cl- -activated aminopeptidase was purified from the cytosol of human erythrocytes as a single chain protein of an approx. Mr of 70,000 and pI of 5.1. The enzyme hydrolysed 2-naphthylamides of aliphatic, aromatic and basic L-amino acids, with a preference for the alanyl residue. It also hydrolysed di-, tri-, and some hydrophobic tetrapeptides. The inhibitors were bestatin, amastatin, Co2+, Zn2+, Mn2+, 4-hydroxymercuribenzoate and 1,10-phenanthroline. The activity of the enzyme, inhibited by 4-hydroxymercuribenzoate, was partially restored by the addition of sulfhydryl compounds. The presence of 0.2 M Cl- (Br-,F-) caused a several-fold increase in the isolated aminopeptidase activity.
Abramić
M
M
Dept Organic Chemistry and Biochemistry, Ruder Bosković Institute, Zagreb, Yugoslavia.
Vitale
L
L
D000626:Aminopeptidases / Q000097:blood*; D002712:Chlorides / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D013379:Substrate Specificity
D002712:Chlorides; D000626:Aminopeptidases