A hydroxysteroid sulfotransferase from rat liver

Abstract

The major hydroxysteroid sulfotransferase found in the livers of female rats has been purified to homogeneity and found to catalyze the transfer of sulfate to any of several hydroxysteroids including dehydroepiandrosterone, estradiol, testosterone, and androstenediol thus forming the corresponding sulfate esters. 3′-Phosphoadenosine 5′-phosphosulfate is the sulfate donor. The reaction is competitively inhibited by both reaction products, i.e., dehydroepiandrosterone sulfate or adenosine 3′,5′-bisphosphate, and also by high concentrations of inorganic phosphate. The enzyme has a molecular weight of approximately 290,000; sodium dodecyl sulfate-gel electrophoresis reveals an apparently single species of 32,000. With standard assay conditions, no activity was observed with the purified enzyme when a phenol, a bile acid, or a hydroxamic acid was used as acceptor for sulfate.