α2,3-linked sialic acid (α2,3-Sia)

α2,3-linked sialic acid residues are terminal monosaccharides found on the N-linked glycans of various cell-surface glycoproteins. These residues are synthesized by specific sialyltransferases, such as the ST3Gal family, and serve as critical recognition motifs for both endogenous ligands and exogenous pathogens (Varki, 2008, Nature). In humans, α2,3-linked sialic acids are prominently expressed in the lower respiratory tract, whereas they are the primary linkage type throughout the respiratory and enteric tracts of avian species (Shinya et al., 2006, Nature). This specific linkage is the primary receptor for avian influenza viruses, such as H5N1 and H7N9, facilitating viral attachment and subsequent entry into host cells. Beyond infectious disease, aberrant α2,3-sialylation is frequently observed in various cancers, where it contributes to immune evasion, tumor cell survival, and increased metastatic potential by modulating cell adhesion (Pearce & Laubli, 2016, Glycobiology). Therapeutic strategies targeting these residues include the use of recombinant sialidases, such as DAS181 (Fludase), which enzymatically remove the sialic acid to prevent viral infection (Triana-Baltzer et al., 2009, Antiviral Research).

Other names

Neu5Acα2-3GalAlpha-2,3-sialic acidAvian-type influenza receptorN-acetylneuraminic acid α2,3-galactose

Enzymatic desialylation (cleavage of the terminal sialic acid residue) to prevent pathogen attachment and entry into host cells.