Inhibitors and dipeptide substrates for a microsomal tyrosylsulfotransferase from rat brain

The sulfotransferase associated with a microsomal fraction from rat brain was previously shown to transfer sulfate groups from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to peptides derived from the cholecystokinin (CCK) molecule. Three tyrosine-containing dipeptide derivatives, i.e., Cbz-Glu-Tyr, Cbz-Gly-Tyr and Ac-Phe-Tyr are shown here to accept the [35S] sulfate group from [35S] PAPS under the action of this sulfotransferase. The sulfotransferase activity evaluated with either any of these dipeptide derivatives or CCK-8 as acceptors is similarly inhibited by a series of compounds, i.e., lipophilic polycyclic compounds like fluphenazine, tyrosine derivatives like Boc-O-benzyl-tyrosine and phenolsulfotransferase inhibitors like 4,4-di-isothiocyano 2',2'-disulfonic acid stilbene.