Alpha-2,3-linked sialic acid-bearing glycoproteins

Cell-surface 2,3-linked sialic acid-bearing glycoproteins are a class of glycoconjugates where N-acetylneuraminic acid is attached to terminal galactose residues via an alpha-2,3-glycosidic bond (Varki, 2017, Glycobiology, 27(1):3-49). These molecules are predominantly found in the lower respiratory tract of humans and serve as the primary receptors for avian influenza viruses, such as H5N1 and H7N9 (Shinya et al., 2006, Nature, 440(7083):435-436). In contrast, human-adapted influenza viruses typically prefer alpha-2,6-linked sialic acids found in the upper respiratory tract (Nicholls et al., 2007, The Lancet, 370(9602):1841-1851). Beyond their role in viral entry, these glycoproteins are involved in critical biological processes including cell-cell adhesion, signal transduction, and immune system modulation. Therapeutic strategies targeting these molecules often utilize host-directed sialidases, such as DAS181, which enzymatically remove the sialic acid residues to prevent viral attachment and subsequent infection (Malakhov et al., 2006, Antimicrobial Agents and Chemotherapy, 50(4):1470-1479). Additionally, altered expression of these glycoproteins is a hallmark of certain cancers, where they contribute to tumor progression and metastatic potential.

Other names

Alpha-2,3-linked sialylglycoconjugatesNeu5Ac-alpha-2,3-Gal receptorsAvian influenza receptorsSA-alpha-2,3-Gal2,3-sialylated glycoproteins

Enzymatic cleavage of terminal alpha-2,3-linked sialic acid residues from the host cell surface to prevent viral attachment and entry (Malakhov et al., 2006, Antimicrobial Agents and Chemotherapy, 50(4):1470-1479).