True or False Influenza virus hemagglutinin binds to sialic

True or False?

Influenza virus hemagglutinin binds to sialic acid residues at the termini of oligosaccharides on cell surface glycolipids and gycoproteins.

Solution

Answer: True

Influenza A viruses possess two surface spike proteins, hemagglutinin (HA) and neuraminidase (NA). The HA protein, a trimeric type I membrane protein, is responsible for binding to sialyloligosaccharides (oligosaccharides containing terminal sialic acid linked to galactose) on host cell surface glycoproteins or glycolipids. This protein is also responsible for fusion between viral and host cell membranes, following virion internalization by endocytosis. Neuraminidase (NA), a tetrameric type II membrane protein, is a sialidase that cleaves terminal sialic acid residues from the glycoconjugates of host cells and the HA and NA and thus is recognized as a receptor-destroying enzyme.