Studies on the purification of rat liver uridine diphosphate glucuronyltransferase

Abstract

A stable, more highly purified, preparation of UDP-glucuronyltransferase (EC 2.4.1.17) was obtained than previously reported. Enzyme activity towards o-aminophenol and p-nitrophenol was increased 43- and 46-fold, respectively. The final preparation contains only 3 staining polypeptide bands visible after sodium dodecyl sulfate/polyacrylamide-gel electrophoresis. The only known major accompanying protein appears to be epoxide hydratase. The purified enzyme activity towards o-aminophenol can still be activated 3-fold by diethylnitrosamine. On evidence from purification, o-aminophenol and p-nitrophenol appear to be glucuronidated by the same enzyme protein. The possible recognition of the UDP-glucuronyltransferase enzyme is discussed.