UDPglukoz

UDP-glucose, or uridine diphosphate glucose, is a nucleotide sugar that acts as an activated donor of glucose residues in various biosynthetic pathways. It is formed from glucose-1-phosphate and uridine triphosphate (UTP) by the enzyme UDP-glucose pyrophosphorylase.

As a glycosyl donor, UDP-glucose participates in the synthesis of numerous carbohydrates and glycoconjugates. In plants, it serves as a substrate for cellulose and other cell wall polysaccharides, and it also participates in the formation of sucrose through the sucrose biosynthetic pathway. In animals and fungi, UDP-glucose provides glucose units for glycogen synthesis and for various glycosylation reactions that attach sugars to proteins and lipids.

In bacteria, UDP-glucose is a versatile precursor in cell wall and capsule biosynthesis. It can be converted to UDP-glucuronic acid by UDP-glucose dehydrogenase, feeding into pathways that produce uronic acids used in extracellular polysaccharides and lipopolysaccharides in some species.

Key enzymes associated with UDP-glucose include UDP-glucose pyrophosphorylase, which produces UDP-glucose from glucose-1-phosphate and UTP; UDP-glucose 6-dehydrogenase, which generates UDP-glucuronic acid; and various glycosyltransferases that transfer the glucose moiety to acceptor molecules. Regulation of UDP-glucose levels influences carbohydrate metabolism, cell wall formation, and glycoprotein biosynthesis across different organisms.