PHENOL SULFOTRANSFERASES

Abstract

Two phenol sulfotransferases were purified from rat liver by conventional techniques coupled with affinity chromatography on Affi-Gel blue and ATP-agarose. Both enzymes are homogeneous by the criterion of sodium dodecyl sulfate gel electrophoresis. Each MW of approximately 65,000 and consists of 2 subunits of apparently equal size. The enzymes are similar in specificity and in their kinetic parameters but differ in amino acid composition and in their elution from DEAE-cellulose. With adenosine 3''-phosphate 5''-phosphosulfate as donor, a large variety of phenolic compounds serve as sulfate acceptor; sterols, simple alcohols, bile acids, and hydroxamates do not serve as substrates. The transferases may be considered as detoxification enzymes which catalyze the conjugation of xenobiotics containing a phenol group or of phenolic compounds generated by endogenous oxidation. The enzymes act on 3-hydroxyindole to yield indican, suggesting that their in vivo function may include the production of this normal tryptophan metabolite.