alpha28sialyltransferase

alpha28sialyltransferase is an enzyme that plays a role in the synthesis of complex carbohydrates, specifically in the modification of glycans. It catalyzes the transfer of a sialic acid residue, N-acetylneuraminic acid (Neu5Ac), from a donor molecule, typically cytidine-5'-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac), to an acceptor molecule. The "alpha28" in its name refers to the specific glycosidic linkage formed, where the sialic acid is attached to the alpha-2,8 position of a terminal sialic acid residue on the glycan chain. This type of linkage is particularly important in the formation of polysialic acid (polySia) chains.

Polysialic acid is a linear homopolymer of Neu5Ac residues linked alpha2-8. It is found on the surface of cells and is involved in a variety of biological processes. The activity of alpha28sialyltransferase is crucial for the elongation and maintenance of these polySia chains. The enzyme is expressed in various tissues and is particularly abundant in the developing nervous system. Aberrant expression or activity of alpha28sialyltransferase has been linked to developmental disorders and certain diseases, including cancer and neurodegenerative conditions. Research into the structure, function, and regulation of alpha28sialyltransferase is ongoing, aiming to understand its precise roles in cellular signaling and development, and to explore its potential as a therapeutic target.