Partial purification and properties of an enzyme from rat liver that catalyses the sulphation of L-tyrosyl derivatives.
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.
D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D002854:Chromatography, Paper; D005260:Female; D005978:Glutathione / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D009596:Nitrophenols; D051381:Rats; D013431:Sulfates / Q000096:biosynthesis; D013460:Sulfur Isotopes; D014166:Transferases / Q000032:analysis / Q000302:isolation & purification*; D014443:Tyrosine / Q000096:biosynthesis
D000227:Adenine Nucleotides; D009596:Nitrophenols; D013431:Sulfates; D013460:Sulfur Isotopes; D014443:Tyrosine; D014166:Transferases; D005978:Glutathione