Bile acid N-acetylglucosaminides. Formation by microsomal N-acetylglucosaminyltransferases in human liver and kidney.

Bile acid N-acetylglucosaminyltransferase activity has been identified in microsomes from human liver and kidney. In both organs the transferases required UDP-N-acetylglucosamine as sugar donor and were mainly active towards ursodeoxycholic acid. Minor activities were observed towards amidated ursodeoxycholic, hyodeoxycholic and beta-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 7 beta-or 6 alpha-hydroxyl groups. Kinetic parameters and other catalytic properties of liver and kidney microsomal N-acetylglucosaminyltransferase activities towards ursodeoxycholic acid are described.