Characteristics of arginases from ureotelic and non-ureotelic animals

Abstract

Livers of ureotelic and uricotelic animals possess the capacity, to a varying extent, of hydrolysing L-arginine and other guanidino compounds. Three different enzymes responsible for such activity have been separated and partially characterized. They are the "ureotelic" arginase, the "uricotelic" arginase (both of them specific for L-arginine) and the guanidinobutyrate ureohydrolase (able to hydrolyse [beta]-guanidinopropionate, gamma-guanidinobutyrate and D-arginine but not L-arginine or guanidinoacetate). The implication of the advent of a "ureotelic" arginase in the integration of the Krebs-Henseleit cycle is discussed.