Bile acid N‐acetylglucosaminides

Abstract

Bile acid N-acetylglucosaminyltransferase activity has been identified in microsomes from human liver and kidney. In both organs the transferases required UDP-N-aeetylglucosamine as sugar donor and were mainly active towards ursodeoxycholic acid. Minor activities were observed towards amidated ursodeoxycholic, hyodeoxycholic and β-muricholic acids. No N-acetylglucosaminidation was detectable with the major primary and secondary bile acids suggesting a specific requirement of the enzymes for bile acids containing 7β- or 6α-hydroxyl groups. Kinetic parameters and other catalytic properties of liver and kidney microsomal N-acetylglucosaminyltransferase activities towards ursodeoxycholic acid are described.