Influenza hemagglutinin: a homotrimeric glycoprotein that is found on the surface of influenza viruses which is responsible for their infectivity. [13] Influenza strains are named for the specific hemagglutinin variant they produce, along with the specific variant of another surface protein, neuraminidase. These hemagglutinins are subject to rapid evolution via antigenic shift and drift …

The polypeptide and subdomain structure of hemagglutinin (HA). (A) An HA trimer of the H1 subtype with one subunit colored according to subdomains with the other two subunits in silver. From membrane-distal to membrane-anchor subdomains: the receptor-binding subdomain (blue), the vestigial esterase subdomain (yellow), the fusion subdomain (red), and the membrane …

Hemagglutinin, any of a group of naturally occurring glycoproteins that cause red blood cells (erythrocytes) to agglutinate, or clump together. These substances are found in plants, invertebrates, and certain microorganisms. Among the best-characterized hemagglutinins are those that occur as

Influenza viruses are classified based on their antigenicity, which is determined by their surface glycoproteins. Four types of influenza viruses, A, B, C, and D, have been isolated and characterized. Influenza A and B viruses have two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), whereas influenza C and D viruses have only one surface glycoprotein, …

2021年10月1日 · Hemagglutinins (HAs) are the receptor-binding and membrane fusion glycoproteins of influenza viruses. They recognize sialic acid-containing, cell-surface glycoconjugates as receptors but have limited affinity for them, and, as a consequence, virus attachment to cells requires their interaction with …

Abstract Influenza virus hemagglutinin (HA) contains antigenic sites recognized by the host immune system, cleavage sites cleaved by host proteases, receptor binding sites attaching to sialyl receptors on the target cell, and fusion peptides mediating membrane fusion. Change in an amino acid (s) in these sites may affect the potential of virus infection and spread within and …

2023年4月28日 · Article Open access Published: 28 April 2023 Structural characterisation of hemagglutinin from seven Influenza A H1N1 strains reveal diversity in the C05 antibody recognition site Seyed Mohammad ...

2020年6月8日 · HEMAGGLUTININ STRUCTURE emagglutinins (HAs) project from the virus Hsurface membrane, as 30–50 Å-diameter, 135 Å-long glycoprotein spikes (Wasilewski et al. 2012). Each spike contains three identical subunits formed of two glycopolypeptides, HA1 and HA2. The subunits are divided into four subdomains: the membrane-distal receptor-binding …

Hemagglutination is used for the diagnosis of some enveloped viruses such as influenza viruses. This method relies on the specific feature of some enveloped viruses that can adsorb to red blood cells (RBCs). Specifically, hemagglutinin 5 (HA), an envelope glycoprotein of some enveloped viruses, imparts this property. In the absence of virus particles, RBCs precipitate by gravity to …

2014年1月1日 · The hemagglutinin (HA) is a prime determinant of the pathogenicity of influenza A viruses. It initiates infection by binding to cell surface receptors and by inducing membrane fusion. The fusion capacity of HA depends on cleavage activation by host proteases, and it has long been known that highly pathogenic avian influenza viruses displaying a multibasic cleavage …