Cerebroside sulfotransferase in rat gastric mucosa.
1. Cerebroside sulfotransferase activity was demonstrated in rat gastric mucosa. This enzyme preparation catalyzes the transfer of sulfate group from 3'-phosphoadenosine-5'-phosphosulfate to added cerebroside and lactosylceramide. 2. Psychosine also serves as an acceptor for sulfate group. 3. Both hydroxy-fatty acid and non-hydroxy-fatty acid containing cerebrosides are equally sulfated. However, this enzyme is inactive toward glucosylceramide. 4. The optimum pH is around 6.0. The reaction is stimulated by the addition of 0.4-0.9% of Triton X-100. 5. The presence of 2-4 mM ATP moderately stimulates the reaction, but is inhibitory when the concentration exceeds 6 mM. 6. EDTA has no effect. 7. Both Mg2+ and Ca2+ stimulate at lower concentrations (less than 16 mM), but inhibit at higher concentrations (greater than 20 mM). Mn2+, however, is a strong inhibitor even at 8 mM concentration. 8. The apparent Km for cerebroside is 0.04 mM, while that for 3'-phosphoadenosine-5'-phosphosulfate is 0.45 microM.
D000818:Animals; D002554:Cerebrosides; D005753:Gastric Mucosa / Q000201:enzymology*; D007790:Lactosylceramides; D008297:Male; D010724:Phosphoadenosine Phosphosulfate; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity; D015238:Sulfotransferases; D013466:Sulfurtransferases / Q000378:metabolism*
D002554:Cerebrosides; D007790:Lactosylceramides; D010724:Phosphoadenosine Phosphosulfate; D013466:Sulfurtransferases; D015238:Sulfotransferases; C020556:galactosylceramide sulfotransferase