An Open Receptor-Binding Cavity of Hemagglutinin-Esterase-Fusion Glycoprotein from Newly-Identified Influenza D Virus: Basis for Its Broad Cell Tropism
Fig 1
Receptor specificity of the IDV HEF protein.
(A) Glycan microarray analyses of the IDV enzymatically inactive HEF (HEF-mut) protein using the CFG glycan microarray. Binding to different types of glycans on the array is highlighted, where magenta represents Neu5Gc, blue represents α2-8-ligands, cyan represents α2-6-ligands, green represents α2-3-ligands, red represents Neu5,9Ac2 and yellow represents other glycans. The HEF-mut protein displayed a good avidity to Neu5,9Ac2 ligands. The structure formulas of the top representative are shown. Error bars represent the standard deviation (SD) of the mean value. Percent coefficient of variation (%CV) = 100×standard deviation/mean. A %CV of less than 50% indicates data reliability. (B) Glycan microarray analysis of IDV HEF-mut proteins using a more extended paired array. The library of glycans tested was designed to test the influence on protein binding of (1) glycosidic linkage of 9-O-Ac-Sia (α2–3 versus α2–6) and (2) modifications at C5 (N-acetylation, 5-N-Ac, versus N-glycosylation, 5-N-Gc). Data presented as mean ± SD.