Extrahepatic sulfation of phenols. Bovine lung and intestinal phenol sulfotransferases.

Phenol sulfotransferases (PST) from bovine lung and small intestine were purified about 1000-fold. PST from bovine small intestine, similarly as the bovine lung enzyme, catalyzes sulfation of only exogenous phenols. A single thermostable form of PST, active with high concentrations of phenol (Km = 1.43 mM) was found in the small intestine. The effect of divalent cations on the activity of the two phenol sulfotransferases was determined. The molecular weight of the native enzymes was estimated as about 69,000 and subunit molecular weight determined by sodium dodecyl sulfate gel electrophoresis as 35,000. In double immunodiffusion tests the bovine lung PST showed antigenic identity with the bovine small intestine enzyme but complete immunological incompatibility with rat liver sulfotransferase.