alfa23sialyltransferaasit

Alpha2,3-sialyltransferases are a family of enzymes that play a crucial role in the biosynthesis of complex carbohydrates, specifically in the addition of sialic acid residues to acceptor molecules. These enzymes catalyze the transfer of N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc) from a donor substrate, typically cytidine-5'-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac), to a terminal galactose or N-acetylgalactosamine residue on a growing oligosaccharide chain. This process results in the formation of an alpha2,3-sialyl linkage.

The specific linkage formed by alpha2,3-sialyltransferases is important because it influences the biological functions of the glycoconjugates they modify. These enzymes are found in various organisms, including mammals, birds, and fish, and are involved in a wide range of physiological processes. For instance, they are essential for the proper development of the nervous system, immune responses, and cell-cell recognition. Aberrant expression or activity of alpha2,3-sialyltransferases has been linked to various diseases, including cancer and inflammatory disorders.

There are several distinct alpha2,3-sialyltransferase genes in mammals, each with varying substrate specificities and tissue distributions. These enzymes are classified based on their substrate preference, such as those that act on N-glycans, O-glycans, or glycolipids. Understanding the precise roles and regulation of these enzymes is an active area of research, with implications for the development of novel therapeutic strategies targeting glycosylation-related diseases.