Complex-type N-glycan (N-glycan)

Complex-type N-glycans are a diverse class of oligosaccharides covalently attached to the asparagine residues of cell-surface and secreted glycoproteins via an N-glycosidic bond. They are characterized by a conserved pentasaccharide core (Man3GlcNAc2) with additional branches, or antennae, initiated by N-acetylglucosamine and often terminating in residues such as galactose, fucose, or sialic acid (Varki et al., Essentials of Glycobiology, 2015). These structures are essential for maintaining protein conformation, protecting against proteolysis, and mediating critical biological processes including cell-cell adhesion and immune system signaling (Moremen et al., Nature Reviews Molecular Cell Biology, 2012). In pathological states, particularly cancer, alterations in N-glycan branching and terminal sialylation are frequently observed, contributing to tumor metastasis and immune evasion (Pinho & Reis, Nature Reviews Cancer, 2015). Consequently, these glycans serve as vital therapeutic targets for broadly neutralizing antibodies in HIV treatment and as docking sites for various pathogens, including the influenza virus and SARS-CoV-2 (Watanabe et al., Nature Communications, 2020).

Other names

Complex N-linked oligosaccharideN-linked glycanAsparagine-linked glycanComplex-type N-linked carbohydrate

Drugs targeting complex-type N-glycans typically function by binding to specific glycan epitopes to block viral entry, inhibiting glycan-cleaving enzymes to prevent pathogen release, or utilizing glycan-binding antibodies to trigger antibody-dependent cellular cytotoxicity (ADCC) against tumor cells. Some therapies also involve metabolic inhibition of glycan synthesis or the use of glycan mimetics to competitively inhibit cell adhesion molecules like selectins.