ADY tripeptide is a minimum sequence for Tyrosylprotein sulfotransferases 1 and 2 substrate recognition

Tyrosylprotein sulfotransferases (TPSTs) catalyze the transfer of a sulphonate moiety from 3'-Phosphoadenosine 5'-Phosphosulfate (PAPS) to the hydroxyl group of a tyrosine residue in substrate proteins. The positively charged substrate binding region of TPST homodimer interacts with acidic residues located in N-terminal region from the sulfated tyrosine in substrates. However, the sequence pattern in TPST substrate recognition remains unclear. Therefore, we aimed to determine the minimum recognition chain length required for tyrosine sulfation. We prepared His-tagged polypeptide, His-TPST1_43-370 and His-TPST2_43-377, form 43-370 of TPST1 and 43-377 of TPST2. Next, we prepared a series of synthesized ADYAE peptides and used a combination of reverse phase high-performance liquid chromatography (RP-HPLC) and mass spectrometric analysis to show that the tripeptide amino acid sequence, ADY, was sulfated by TPST1 and TPST2. Furthermore, we found that the acidic residue, located two residues C-terminal region from the tyrosine residue, may be involved in the TPST-induced sulfation regulation. The results in our study propose that proteins with the ADY sequence may be useful for searching the novel TPST tyrosine sulfated substrates.