Substance that causes red blood cells to agglutinate
Illustration showing influenza virus attaching to cell membrane via the surface protein hemagglutinin
In molecular biology , hemagglutinins (alternatively spelt haemagglutinin , from the Greek haima , 'blood' + Latin gluten , 'glue') are receptor-binding membrane fusion glycoproteins produced by viruses in the Paramyxoviridae and Orthomyxoviridae families.[ 1] [ 2] Hemagglutinins are responsible for binding to receptors on host cells to initiate viral attachment and infection .[ 3]
Hemagglutinins recognize cell-surface glycoconjugates containing sialic acid on the surface of host red blood cells with a low affinity and use them to enter the endosome of host cells.[ 4] In the endosome, hemagglutinins are activated at a pH of 5–6.5 to undergo conformational changes that enable viral attachment through a fusion peptide .[ 5]
Virologist George K. Hirst discovered agglutination and hemagglutinins in 1941.[ 6] Alfred Gottschalk proved in 1957 that hemagglutinins bind a virus to a host cell by attaching to sialic acids on carbohydrate side chains of cell-membrane glycoproteins and glycolipids .[ 7]
The name "hemagglutinin" comes from the protein 's ability to cause red blood cells (erythrocytes) to clump together ("agglutinate ") in vitro .[ 8]
^ Couch, Robert B. (1996), Baron, Samuel (ed.), "Orthomyxoviruses" , Medical Microbiology (4th ed.), Galveston (TX): University of Texas Medical Branch at Galveston, ISBN 978-0-9631172-1-2 , PMID 21413353 , retrieved 30 January 2024
^ "Paramyxoviridae - an overview | ScienceDirect Topics" . www.sciencedirect.com . Retrieved 30 January 2024 .
^ Nobusawa, E. (October 1997). "[Structure and function of the hemagglutinin of influenza viruses]" . Nihon Rinsho. Japanese Journal of Clinical Medicine . 55 (10): 2562–2569. ISSN 0047-1852 . PMID 9360372 .
^ Bangaru, Sandhya; Lang, Shanshan; Schotsaert, Michael; Vanderven, Hillary A.; Zhu, Xueyong; Kose, Nurgun; Bombardi, Robin; Finn, Jessica A.; Kent, Stephen J.; Gilchuk, Pavlo; Gilchuk, Iuliia (2019). "A Site of Vulnerability on the Influenza Virus Hemagglutinin Head Domain Trimer Interface" . Cell . 177 (5): 1136–1152.e18. doi :10.1016/j.cell.2019.04.011 . PMC 6629437 . PMID 31100268 .
^ Medeiros, R.; Escriou, N.; Naffakh, N.; Manuguerra, J. C.; van der Werf, S. (10 October 2001). "Hemagglutinin residues of recent human A(H3N2) influenza viruses that contribute to the inability to agglutinate chicken erythrocytes" . Virology . 289 (1): 74–85. doi :10.1006/viro.2001.1121 . ISSN 0042-6822 . PMID 11601919 .
^ Kolata, Gina (26 January 1994). "George Keble Hirst, 84, Is Dead; A Pioneer in Molecular Virology" . The New York Times . ISSN 0362-4331 . Retrieved 14 May 2024 .
^ Henry, Ronnie; Murphy, Frederick A. (October 2018). "Etymologia: Hemagglutinin and Neuraminidase" . Emerging Infectious Diseases . 24 (10): 1849. doi :10.3201/eid2410.ET2410 . PMC 6154157 .
^ Nelson DL, Cox MM (2005). Lehninger's Principles of Biochemistry (4th ed.). New York: WH Freeman.