Hemagglutinin

Definition

Hemagglutinin is a glycoprotein found on the surface of certain viruses, such as the influenza virus, that causes red blood cells to clump together. It plays a crucial role in the initial stages of viral infection by binding to host cell receptors.

5 Must Know Facts For Your Next Test

1. Hemagglutinin facilitates the entry of the virus into host cells by binding to sialic acid-containing receptors.
2. It is one of the main antigens targeted by the immune system during an influenza infection.
3. Hemagglutinin undergoes frequent mutations, leading to antigenic drift and making it challenging for vaccines to provide long-term protection.
4. The effectiveness of hemagglutination assays relies on this glycoprotein's ability to agglutinate red blood cells.
5. Different subtypes of hemagglutinin are designated by numbers (e.g., H1, H3) and are used in naming influenza strains (e.g., H1N1).

Review Questions

• What role does hemagglutinin play in viral infections?
• How does hemagglutinin contribute to the challenges in developing long-term effective vaccines for influenza?
• Why is hemagglutinin important in agglutination assays?

Related terms

Neuraminidase:

Another glycoprotein on the surface of influenza viruses that helps release newly formed viruses from host cells.

Antigenic Drift:

The process by which small genetic changes occur in viral genes coding for surface proteins like hemagglutinin.

Agglutination Assay: A laboratory method used to detect and measure antibodies or antigens through their ability to cause clumping of specific particles.