Bile salt sulfotransferase in guinea pig liver

Abstract

Bile salt sulfotransferase from guinea pig liver is purified by the procedures of ammonium sulfate fractionation, Sephadex G-100 column chromatography, agarose-hexane-adenosine 3′,5′-diphosphate affinity chromatography and polyacrylamide gel electrophoresis. The purified enzyme exhibits a pH optimum of 6.8, an isoelectric point of 5.6 and a molecular weight of 7600 estimated by gel filtration technique. The apparent K m values of the enzyme are 7.7·10 −5 M for taurolithocholate and 1.4·10 −6 M for 3′-phosphoadenosine 5′-phosphosulfate. It requires Mg 2+ and free sulfohydryl group(s) for activity. The enzyme reacts with hydroxy groups of bile salts at both 3α and 3β positions. No activity is found in the kidney of guinea pig. The purified enzyme does not react with estrone, estradiol, testosterone, dehydroepiandrosterone, cholesterol, phenol, tyramine, and serotonin. The results indicate that bile salt sulfotransferase is distinct from other hepatic sulfotransferases.