The identity of alcohol sulfotransferases with hydroxysteroid sulfotransferases

Abstract

Hydroxysteroid sulfotransferase 1, an enzyme effective in the transfer of sulfate from adenosine 3′-phosphate-5′-phosphosulfate to a wide variety of hydroxysteroids, was purified to homogeneity from rat liver. The protein is 180,000 daltons with subunits of 28,000 daltons. The actual specificity of the enzyme is not limited to hydroxysteroids. Rather, a wide range of alcohols were found to serve as sulfate acceptors. Among these are the primary aliphatic alcohols that have a lower apparent K_m and high apparent V as a function of increasing chain length beginning with ethanol. Hydroxysteroids with either a primary or secondary alcohol group are substrates but estrone, with a phenolic hydroxyl group, is not. Secondary alcohols that are substrates include ascorbic acid, chloramphenicol, ephedrine, propranolol, and vitamin D. Sterol sulfotransferase 2, a homogeneous enzyme preparation, and sulfotransferase 3, a preparation of approximately 90% purity, are similar to sulfotransferase 1 in their specificity for primary and secondary alcohols.