UDPglucosyltransferases

UDP‑glucosyltransferases (UGTs) are a family of enzymes that catalyze the transfer of a glucose moiety from uridine diphosphate glucose (UDP‑glucose) to a variety of acceptor molecules. They are critical for the biosynthesis of glucoside conjugates in plants and for the metabolic detoxification of endogenous and xenobiotic compounds in animals. The reaction typically proceeds through a nucleophilic attack of the acceptor’s hydroxyl or amino group on the anomeric carbon of the glucose, forming an O‑ or N‑glucoside linkage and releasing UDP.

UGTs are classified according to the sequence and structural features of the catalytic domain. In humans, the UGT1A and UGT2B families are the most studied; they share a common catalytic core but differ in their substrate recognition sites. Plant UGTs, such as UGT73, GGT1, or UGT80, often possess additional regulatory domains that modulate expression in response to developmental cues or environmental stresses.

The enzymatic activity of UGTs influences plant defense, pigmentation, hormone regulation, and the storage of secondary metabolites. In mammals, UGTs play a pivotal role in glucuronidation, a major phase‑II metabolic pathway that enhances solubility of lipophilic substances, thereby facilitating excretion. Genetic polymorphisms in UGT genes have been linked to altered drug metabolism, affecting therapeutic efficacy and toxicity of many pharmaceuticals.

Industrial applications of UDP‑glucosyltransferases include the synthesis of sugar‑modified natural products, improving the flavor, stability, and pharmacokinetics of active compounds. Engineering of UGTs through protein‑engineering techniques is an active area of research, aiming to expand substrate scope and catalytic efficiency for biocatalysis and synthetic biology.