Investigation of 5 β-scymnol sulfotransferases from the kidney and testis of Heterodontus portusjacksoni

Abstract

An enzyme system that catalyzes the transfer of the sulfate group from 3′-phosphoadenosine 5′-phosphosulfate to two C 27 bile salts has been isolated from cytosolic fractions of the kidney and testis from the shark Heterodontus portusjacksoni. The kidney sulfotransferase was partially purified by a combination of adsorption (hydroxylapatite) and exclusion (Sephadex G-100) chromatography with the native molecular weight of the sulfotransferase estimated to be 80 kDa. The two tissue sulfotransferase fractions were characterized and found to have similar pH and temperature ranges, were activated by magnesium ions and inhibited by the product. Both of the enzymes were able to sulfate the C 27 bile salts 5 β-scymnol (the natural bile salt) and 5 α-cyprinol (the carp bile salt) and displayed Michaelis-Menten kinetics with the substrate 5 β-scymnol. These results represent the first investigation of an elasmobranch kidney and testis scymnol sulfotransferase.