Sialic acid residues on glycoconjugates

Sialic acid residues are nine-carbon monosaccharides, primarily N-acetylneuraminic acid (Neu5Ac), attached as terminal components to glycoproteins, glycolipids, and proteoglycans on cell surfaces, forming the glycocalyx. They are added via α2,3-, α2,6-, or α2,8-linkages by Golgi sialyltransferases using CMP-Neu5Ac, conferring negative charge, hydrophilicity, and bulkiness that mediate anti-adhesive properties, self-recognition (e.g., by Siglecs and Factor H), leukocyte rolling via sialyl-Lewis X, and protection from clearance or degradation. Removal occurs by sialidases in endosomes, lysosomes, or at the plasma membrane. While not a discrete receptor or protein target, these residues are functional elements influencing pathophysiology, but no approved drugs directly target them as a canonical therapeutic entity.

Other names

Sialic acidsSialoglycoconjugatesTerminal sialic acidsNeu5Ac residues