espectively)9,11,53,84–86. 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-a