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Arginase from human full-term placenta

1976; Portland Press; Volume: 159; Issue: 3 Linguagem: Inglês

10.1042/bj1590579

1470-8728

Raffaele Porta, Carla Esposito, A.M. Martin, G. Della Pietra,

Amino Acid Enzymes and Metabolism

Arginase was purified about 1800-fold from extracts of human full-term placenta; the enzyme appeared to be homogenous by disc electrophoresis and molecular-sieve chromatography. The mol. wt. determination by gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis yielded a value of 70000 for the most pure and the partially purified enzyme. The human placenta arginase is a metalloenzyme with an optimum pH of 9.1. The Km for L-arginine is 27 mM. L-Ornithine and L-lysine show competitive inhibition with Ki values of 6.3 and 14 mM respectively.