The Kinetics of Urease Activity in Corynebacterium renale

Abstract

Whole organisms of C. renale, the causative organism of a specific bovine pyelonephritis, have a high urease activity which is rapidly inactivated by atmospheric O2. The enzyme is constitutive: activity does not increase if organisms are grown in urea media. Studies with ceil-free extracts indicate an optimum pH of 7.5, a Michaelis constant of 0.030[image], and a temperature velocity constant of 7800 cal. Of 17 analogues of urea, only thiourea had any inhibitory effect. The pathogenicity of C. renale may be due to local accumulation of ammonia in the kidney, but the part played by urease in the etiology of the disease remains obscure.