Phenol sulfotransferase in human lung.

Human lung phenol sulfotransferase was about 1000-fold purified using the earlier described procedure. 2-Naphthol, p-nitrophenol, phenol, salicylamide, p-methylphenol, o-methoxyphenol, adrenaline, and dopamine were tested as substrates for human lung PST using the barium hydroxide procedure and the ECTEOLA-cellulose method. Km values for sulfate donor (PAPS) and for different sulfate acceptors were determined. 2,6-Dichloro-4-nitrophenol was found to be a competitive inhibitor of human lung PST with Ki = 8.87 +/- 0.08 microM. High salt concentration and Mg2+, Mn2+, and Zn2+ inhibited lung PST. The molecular weight of human lung PST was estimated as 38,000 and 35,000 by gel filtration and SDS-gel electrophoresis, respectively.