Studies in detoxication. 35. Spectrophotometric determination of β-glucuronidase using p-chlorophenylglucuronide as substrate

Abstract

Beta-Glucuronidase was determined spectrophoto-metrically using p-chlorophenylglucuronide as substrate, since p-chlorophenol in alkali had absorption bands at 245 and 298 m[mu] where the absorption of the glucuronide was negligible. The method was applied to an ox spleen glucuronidase prepn. and the results examined by the analytical methods of Lineweaver and Burk (1934). The inhibition of the enzyme by excess substrate was shown to be competitive. Various constants for the action of beta-glucuronidase on p-chlorophenylglucuronide were calculated. Inhibition of the enzyme by D-glucosaccharic, mucic and D-glucuronic acids and D-glucurone was studied. Glucurone was found to be non-inhibitory and the powerful inhibitory action of glucosaccharic acid was confirmed.