Viral surface protein glycans

Viral surface protein glycans are complex carbohydrate structures covalently attached to viral envelope or spike proteins, forming a dense "glycan shield" that physically masks conserved protein epitopes from the host immune system (Watanabe et al., 2020, Nat Commun). These glycans are essential for the biological fitness of viruses such as HIV-1, Influenza, and SARS-CoV-2, as they facilitate proper protein folding within the host endoplasmic reticulum and ensure the structural integrity of the mature virion (Bagdonaite & Wandall, 2018, Glycobiology). Beyond shielding, specific glycans can act as ligands for host cell receptors, such as C-type lectins, directly mediating viral attachment and subsequent entry into target cells (Vigerust & Shepherd, 2007, Trends Microbiol). In therapeutic development, these glycans are targeted by broadly neutralizing antibodies (bNAbs) that recognize conserved clusters of high-mannose glycans, as well as by lectins like Griffithsin that block viral fusion (Sok et al., 2016, Science; O'Keefe et al., 2009, PNAS). However, the high similarity between viral and host glycosylation patterns, combined with the virus's ability to shift glycan positions to escape immune pressure, presents significant challenges for achieving high specificity and long-term efficacy (Crispin et al., 2018, Chem Rev).

Other names

Viral envelope glycansGlycan shieldViral N-glycansViral O-glycansViral carbohydrate epitopesViral spike glycans

Drugs targeting viral surface protein glycans typically function through two primary modalities: direct binding and enzymatic inhibition. Broadly neutralizing antibodies (bNAbs) and lectins bind to conserved glycan patches or "glycan holes" on the viral surface, sterically hindering the interaction between the virus and host cell receptors to prevent entry (Sok et al., 2016, Science; O'Keefe et al., 2009, PNAS). Alternatively, iminosugars like Miglustat inhibit host-cell alpha-glucosidases, leading to the production of misfolded viral glycoproteins that are either degraded or lose their infectious potential (Nash et al., 2011, Antiviral Res).