1. Hemagglutinin (HA):
- HA is a surface glycoprotein that mediates the initial attachment of the influenza virus to host cells.
- It recognizes and binds to specific receptors on the surface of respiratory epithelial cells, such as sialic acids.
- This binding event allows the virus to establish a firm hold on the cell surface, which is crucial for subsequent steps of infection.
2. Neuraminidase (NA):
- NA is another surface glycoprotein of influenza A virus.
- It functions as an enzyme that cleaves sialic acids from the surface of infected cells and virus particles.
- By removing sialic acids, NA helps the virus to detach from infected cells and spread to neighboring cells.
- Additionally, NA plays a crucial role in the release of newly formed viral particles from infected cells.
The coordinated action of HA and NA is essential for the successful entry and replication of influenza A virus within host cells. HA enables the virus to attach to the cell surface, while NA facilitates its release from infected cells. These proteins, along with other viral components, contribute to the overall infectivity and spread of the influenza virus, making them potential targets for antiviral therapies.
