sulfotransferase

Sulfotransferases are enzymes that catalyze the transfer of a sulfo group from the universal sulfate donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to acceptor molecules, producing sulfated products and 3'-phosphoadenosine-5'-phosphate (PAP). The typical outcome is the formation of sulfate esters on alcohols, phenols, sugars, amines, or tyrosine residues, depending on the enzyme and substrate.

Two major groups are recognized in humans. Cytosolic sulfotransferases (SULTs) metabolize a broad range of small molecules, including xenobiotics, hormones, and neurotransmitters; well-studied examples include SULT1A1 and SULT2A1, which sulfate estrogens, catecholamines, and dehydroepiandrosterone, among others. Golgi-associated sulfotransferases include carbohydrate sulfotransferases (CHSTs), which modify glycosaminoglycans and glycoproteins (for example CHST3 involved in chondroitin sulfate sulfation), and tyrosylprotein sulfotransferases (TPST1/TPST2), which sulfate tyrosine residues on secreted and membrane proteins.

Biological roles of sulfotransferases include enhancing the solubility and excretion of compounds (detoxification), modulating hormone activity, and enabling post-translational modification of proteins that affect interactions and signaling. Substrate specificity and tissue distribution vary by isoform, and expression can be developmentally regulated or influenced by hormonal status.

Clinical relevance centers on genetic polymorphisms that affect drug metabolism and disease susceptibility, as well as alterations in sulfation pathways implicated in endocrine regulation, cancer biology, and infectious disease processes.