Characterization of bovine heart sulfotransferase catalyzing the sulfation of tyrosine-containing peptides.
Using [35S]PAPS as the sulfate donor, we have detected a sulfotransferase from bovine heart which catalyzes the sulfation of tyrosine-containing peptides. The enzyme displayed optimal activity at pH 5.75 and 35 degrees C in a one-hour reaction. The addition of 10 mM Mn2+ or Co2+ to the reaction mixture increased the sulfotransferase activity by 3.4- and 3.5-fold, respectively. In contrast, the maximum increment stimulated by Mg2+ was only 1.75-fold at 15 mM concentration, and instead of exerting an enhancement effect, Ca2+ was found to be a potent inhibitor. The addition of 50 mM NaF to the reaction mixture resulted in an increase in sulfotransferase activity of 3.3-fold. The K(m) for 3'-phosphoadenosine 5'-phosphosulfate (PAPS) was determined to be 2 microM at a constant 0.5 mM Boc-Glu-Asp-Tyr-Val. Among the 10 peptides tested as substrates, Boc-Glu-Asp-Tyr-Val and Boc-Asp-Asp-Tyr-Val provided the highest activities.
Suiko
M
M
Department of Biological Resource Sciences, Miyazaki University, Japan.
Fernando
P H
PH
Sakakibara
Y
Y
Kudo
H
H
Nakamura
T
T
Liu
M C
MC
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D003035:Cobalt / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D009206:Myocardium / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010724:Phosphoadenosine Phosphosulfate / Q000378:metabolism; D013379:Substrate Specificity; D013431:Sulfates / Q000378:metabolism*; D015238:Sulfotransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D014443:Tyrosine / Q000378:metabolism*
D004791:Enzyme Inhibitors; D010455:Peptides; D013431:Sulfates; D013462:Sulfur Radioisotopes; D003035:Cobalt; D014443:Tyrosine; D010724:Phosphoadenosine Phosphosulfate; D015238:Sulfotransferases; D002118:Calcium