Fig. 6: Comparison of the glycan shields of viral class I fusion proteins.
From: Vulnerabilities in coronavirus glycan shields despite extensive glycosylation
Glycan shield densities were calculated using Proteins, Interfaces, Structures and Assemblies (PISA)83 analyses of fully glycosylated models of SARS S, MERS S, HKU1 S, LASV GPC, HIV-1 Env (BG505), Influenza H3N2 hemagglutinin (Victoria 2011), SIV Env (PDB ID 5X58, 5X59, 5I08, 5VK2, 4ZMJ, 4O5N, 6OHY, respectively)9,11,53,84,85,86. Oligomannose abundances of viral glycoproteins were ascertained by HILIC-UPLC analysis of PNGase F released N-linked glycans that were fluorescently labelled with procainamide24,45,53 (SI Fig. 5). The number of amino-acid residues interacting with N-linked glycans was divided by the number of solvent-accessible amino-acid residues of the glycoprotein as a measure for global glycan shield density. All viral glycoproteins analysed were expressed as trimers in HEK293F cells apart from LASV GPC, which was derived from virus-like particles from Madin-Darby canine kidney II cells.
