What does influenza hemagglutinin bind to?
The process is like this: Hemagglutinin (HA) binds to the monosaccharide sialic acid which is present on the surface of its target host cells. The cell membrane then engulfs the virus through endocytosis and forms endosome.
How does influenza bind to cells?
To infect cells without getting stuck in the mucus, influenza A relies on a balance between two proteins on the surface of its viral particles: the receptor-binding protein hemagglutinin (HA) and the cleaving protein neuraminidase (NA).
What is the structure of hemagglutinin?
The hemagglutinin molecule is actually a combination of three identical proteins (shown here as gray, green, and purple) that are bound together to form an elongated cylindrical shape. Hemagglutinin consists of a globular head and a stem. The globular head consists of three chains, Chains A, C, and E.
How many amino acids are in the influenza HA protein?
HA (HE) is cleaved into the signal peptide (about 20 amino acids in influenza A viruses), protein HA1 (HE1) (about 320 amino acids), and protein HA2 (HE2) (about 220 amino acids) when mature proteins are produced (fig.
What is the receptor for the influenza virus haemagglutinin?
Influenza haemagglutinin (HA) is a glycoprotein coded in the HA gene segment of the influenza virus and along with neuraminidase, is expressed as a trimer on the surface of the viral capsid.
What is the receptor for Haemagglutinin?
The mature HA protein is responsible for attachment of the virus to its natural receptors, which are terminal sialic acids (N-acetylneuraminic acid (NeuAc)) on glycoprotein and glycolipids on the host cell, and for fusion of the viral envelope with the host cell in the low pH of endosomal compartments (Skehel and Wiley …
What receptor does influenza virus bind to?
As a first step to entry and infection, influenza viruses attach with the HA protein to sialylated glycan receptors on host cells. The influenza virus HA protein is a type I integral membrane glycoprotein, with a N‐terminal signal sequence.
What cell receptor does influenza virus bind?
Sialic acids (SAs) of cell surface glycoproteins and glycolipids are the receptors for the influenza virus, recognized by the viral glycoprotein hemagglutinin (HA; Figure 1). The site on HA at which the cellular receptors are bound is at the distal end of the molecule.
How many amino acids are in hemagglutinin?
The HA2 subunit (221 amino acids) has a hair spin structure composed by two antiparallel alpha-helixes. One of these belongs to the longest alpha-helixes in globular protein: it is 50 angstrom long.
How many residues are in the α helix of the influenza hemagglutinin protein?
The hemagglutinin protein in influenza virus contains a remarkably long α -helix, with 53 residues.