Studies on the alpha-L-iduronidase activity of beta-glucuronidase preparations from bovine liver, rat liver, and rat preputial gland.
A commercial preparation of bovine liver beta-glucuronidase contained two distinct enzyme species, both of which catalyze the hydrolysis of 4-methylumbelliferyl alpha-L-iduronide. The species with a molecular weight of about 290,000 was devoid of phenyl alpha-L-iduronidase activity and exhibited 4-methylumbelliferyl beta-D-glucuronidase activity. The species with a molecular weight of about 78,000 was active towards phenyl alpha-L-iduronide but lacked the latter activity. Studies of the kinetics of inhibition and heat inactivation suggested that the hydrolysis of 4-methylumbelliferyl alpha-L-iduronide is due to the beta-glucuronidase in the case of the 290,000-dalton species. The highly purified beta-glucuronidase preparations derived from rat preputial gland and liver lysosomes also exhibited 4-methylumbelliferyl alpha-L-iduronidase activity. These findings support the view that beta-glucuronidase can hydrolyze certain alpha-L-iduronide bonds and raise the possibility that beta-glucuronidase may play a role in the catabolism of iduronic acid-containing glycosaminoglycans.
D000818:Animals; D002417:Cattle; D005966:Glucuronidase / Q000302:isolation & purification / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D007068:Iduronidase / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D009928:Organ Specificity; D010413:Penis / Q000201:enzymology; D051381:Rats; D012627:Sebaceous Glands / Q000201:enzymology*; D013045:Species Specificity; D013379:Substrate Specificity
D006026:Glycoside Hydrolases; D005966:Glucuronidase; D007068:Iduronidase