Abstract

The immunological characterization of the different forms of phenol sulfotransferase (PST) in a variety of human and nonhuman tissues is described. Immunoblotting techniques revealed that polyclonal antibodies raised to human platelet MII-PST reacted with polypeptides of 32 and 34 kDa from human platelet 100,000 x g supernatant solution. Immunoblot analysis of platelet 100,000 x g supernatant solution that was fractionated over a DEAE-cellulose column indicated a close correspondence of P-PST activity, as measured by phenol sulfation, and M-PST activity, as assessed by dopamine sulfation, with the 32 and 34 kDa polypeptides, respectively. Examination of various human tissues revealed the presence of immunologically detectable levels of P-PST in liver and adrenal gland whereas both M- and P-PST were detected in placenta at a 1/10,000 dilution of the antisera. Under these conditions, PST was undetectable in human frontal cortex, pituitary gland, kidney, lung, and jejunum. Further evaluation of human liver samples from four individuals indicated a strong correlation (r = 0.94) between the amount of 32-kDa immunoreactive protein and P-PST activity. Analysis of liver samples from several animal species (monkey, rat, mouse, guinea pig, and frog) revealed the presence of immunoreactive proteins of various molecular masses, suggesting that considerable homology may exist between human and nonhuman forms of PST.