Publications

• Partial purification and properties of an enzyme from rat liver that catalyses the sulphation of L-tyrosyl derivatives.

  Mattock P., Jones J.G.

  1. An enzyme that catalyses the transfer of sulphate from adenosine 3'-phosphate 5'[(35)S]-sulphatophosphate to l-tyrosine methyl ester and tyramine was purified approx. 70-fold from female rat livers. 2. The partially purified preparation is still contaminated with adenosine 3'-phosphate 5'-sulph ... >> More

  1. An enzyme that catalyses the transfer of sulphate from adenosine 3'-phosphate 5'[(35)S]-sulphatophosphate to l-tyrosine methyl ester and tyramine was purified approx. 70-fold from female rat livers. 2. The partially purified preparation is still contaminated with adenosine 3'-phosphate 5'-sulphatophosphate-phenol sulphotransferase (EC 2.8.2.1), but a partial separation of the two enzymes can be achieved by chromatography on columns of Sephadex G-200 and DEAE-Sephadex. 3. The enzyme responsible for the sulphation of l-tyrosine methyl ester and tyramine is activated by dithiothreitol, 2-mercaptoethanol and GSH, the degree of activation being more marked with preparations previously stored at 0 or -10 degrees C. In contrast, the enzymic sulphation of p-nitrophenol is inhibited by all three thiols. Again, there is a quantitative difference in the degree of inhibition of the two enzymes by o-iodosobenzoate, p-chloromercuribenzoate, N-ethylmaleimide and iodoacetate. 4. Mixed-substrate experiments support the hypothesis that the enzyme responsible for the sulphation of l-tyrosine methyl ester and tyramine is separate from that responsible for the sulphation of p-nitrophenol. However, p-nitrophenol is a potent inhibitor of the sulphation of both tyrosyl derivatives whereas these latter compounds have no effect on the sulphation of p-nitrophenol. << Less

  Biochem J 116:797-803(1970) [PubMed] [EuropePMC]

• On the mechanism of aryl sulfotransferase.

  Duffel M.W., Jakoby W.B.

  Aryl sulfotransferase IV (EC 2.8.2.1), purified to homogeneity from male rat liver, catalyzes the sulfation of a variety of substituted phenols, including catecholamines, tyrosine esters, and peptides containing NH2-terminal tyrosine residues. An investigation of the mechanism of the enzyme was ca ... >> More

  Aryl sulfotransferase IV (EC 2.8.2.1), purified to homogeneity from male rat liver, catalyzes the sulfation of a variety of substituted phenols, including catecholamines, tyrosine esters, and peptides containing NH2-terminal tyrosine residues. An investigation of the mechanism of the enzyme was carried out using 2-chloro-4-nitrophenol as a model substrate. Kinetic, inhibition, and binding studies with aryl sulfotransferase IV are all consistent with a random rapid equilibrium Bi Bi kinetic mechanism with two dead end product inhibitor complexes. Studies of the chemical mechanisms of the enzyme-catalyzed reaction demonstrate that electron-withdrawing substituents decrease the maximal velocity of phenol sulfation. The maximal velocity of the reaction correlates with Hammett sigma p-constants (rho = -0.25). Evidence is presented for the mechanism by which adenosine 3',5'-bisphosphate and aryl sulfotransferase catalyze the transfer of sulfate from 2-chloro-4-nitrophenyl sulfate to other phenols. << Less

  J Biol Chem 256:11123-11127(1981) [PubMed] [EuropePMC]

• Aryl sulfotransferase IV from rat liver.

  Sekura R.D., Jakoby W.B.

  Arch Biochem Biophys 211:352-359(1981) [PubMed] [EuropePMC]