Sialic acid residue

Sialic acid residues are a family of negatively charged nine-carbon monosaccharides, typically found at the terminal positions of glycan chains on glycoproteins and glycolipids on eukaryotic cell surfaces. They play critical roles in cell-cell recognition, communication, and regulation of immune responses, acting as ligands for numerous endogenous lectins, such as Siglecs and selectins. Pathogens like influenza viruses exploit sialic acid residues as receptors for host cell entry, while many bacteria decorate their surfaces with sialic acids for immune evasion through molecular mimicry. Increased sialylation in cancer facilitates immune evasion and metastasis. While neuraminidase inhibitors are established antivirals targeting the viral enzyme that cleaves host sialic acids, there are currently no approved drugs that directly target host cell sialic acid residues due to their essential biological functions and potential safety risks.

Other names

Sialic acidsN-acetylneuraminic acid (Neu5Ac)Sialyl residuesSiaSialylated glycan residues

Prevention of viral attachment/entry (neuraminidase inhibitors prevent cleavage of sialic acid and block budding/release of new viral particles); Inhibition of sialic acid biosynthesis or sialylation alters cell signaling and immune recognition (experimental/chemical biology tools)