sulfotransferázy

Sulfotransferases (SULTs) are a family of enzymes that catalyze the transfer of a sulfo group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to a wide range of substrates, forming sulfate esters or sulfated carbohydrates. The general reaction is substrate-OH + PAPS → substrate-OSO3− + PAP. They play a central role in biotransformation, hormone regulation, and the biosynthesis of extracellular matrix components.

Two major functional groups exist within the sulfotransferases: cytosolic sulfotransferases, which modify small molecules such as drugs, steroids, and neurotransmitters, and Golgi-localized carbohydrate sulfotransferases (CHSTs), which sulfate glycosaminoglycans and other carbohydrates, influencing proteoglycan structure and signaling. SULTs modify xenobiotics and endogenous compounds, while CHSTs contribute to the sulfation patterns that regulate cell–matrix interactions.

Mechanism and specificity vary among isoforms. Cytosolic SULTs typically act on phenols, alcohols, and certain amines, displaying broad or narrow substrate ranges depending on the enzyme. CHSTs operate in the Golgi lumen during polysaccharide biosynthesis and show specificity for sugar moieties and linkage positions. The universal sulfo donor is PAPS, and the reaction yields sulfated product and PAP.

Regulation and genetics: numerous human isoforms (for example SULT1A1, SULT1E1, SULT2A1, SULT2B1) exhibit tissue-specific expression. Enzyme activity is influenced by genetic polymorphisms, developmental stage, disease states, and exposure to inducers or inhibitors.

Clinical and biological significance: sulfation generally increases water solubility to aid excretion and modulates hormone activity and signaling. Variability in SULT activity affects drug response and toxicity, hormone metabolism, and extracellular matrix composition, with implications for health and disease.