Neuraminidase (influenza virus A)

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Neuraminidase
Neuraminidase
Mass / length primary structure 454 amino acids , 50 kDa
Secondary to quaternary structure homotetramer
Cofactor 1 Ca 2+ per subunit
Identifier
External IDs

The neuraminidase is an enzyme and surface protein in the virus envelope of influenza viruses .

properties

Neuraminidase is a membrane protein (single-pass type 2). As a tetrameric neuraminidase, it is a sialidase and cleaves N-acetylneuraminic acid from glycosylations that occur in the glycocalyx of the host's cells , but not as a monomer . As a result of the enzymatic removal of the influenza virus receptor , newly formed influenza viruses are released from the cell membrane of the infected cell; at the same time, the removal of N-acetylneuraminic acid prevents hemagglutinin- mediated binding of influenza viruses to cells already infected, as these, among other things, carry neuraminidase on their cell surface. This results in an improved release of the viruses newly created by the replication (daughter viruses from the infected cells) and thus an increased spread of the infection both within the same organism and to other organisms. In addition, by binding to CD66c , neuraminidase prevents a cell death program from starting in an infected cell . Neuraminidase may be involved in the budding of the newly formed influenza viruses from the cell membrane by binding to lipid rafts . Neuraminidase is a virulence factor and in part determines the tropism of the respective influenza virus strain. The neuraminidases of influenza viruses can be divided serologically into nine different serotypes (N1 to N9). Neutralizing antibodies are often formed against neuraminidase (and especially against hemagglutinin) in the course of an infection or after a vaccination , which prevent re-infection with influenza viruses of the same NA or HA serotype and thus mediate immunity .

Neuraminidase cleaves glycosidic bonds of the types α (2 → 3), α (2 → 6) and α (2 → 8). Oseltamivir , zanamivir and peramivir inhibit neuraminidase in non-resistant Influenza A and Influenza B strains.

Individual evidence

  1. GM Air: Influenza neuraminidase. In: Influenza and other respiratory viruses. Volume 6, number 4, July 2012, ISSN  1750-2659 , pp. 245-256, doi : 10.1111 / j.1750-2659.2011.00304.x , PMID 22085243 , PMC 3290697 (free full text).
  2. Y. Suzuki: Sialobiology of influenza: molecular mechanism of host range variation of influenza viruses. In: Biol Pharm Bull . Vol. 28, 2005, No. 3, pp. 399-408, doi : 10.1248 / bpb.28.399 , PMID 15744059 .
  3. P. Gaur, P. Ranjan, S. Sharma, JR Patel, JB Bowzard, SK Rahman, R. Kumari, S. Gangappa, JM Katz, NJ Cox, RB Lal, S. Sambhara, SK Lal: Influenza A virus neuraminidase protein enhances cell survival through interaction with carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) protein. In: The Journal of biological chemistry. Volume 287, Number 18, April 2012, ISSN  1083-351X , pp. 15109-15117, doi : 10.1074 / jbc.M111.328070 , PMID 22396546 , PMC 3340274 (free full text).
  4. ^ AV Cauldwell, JS Long, O. Moncorgé, WS Barclay: Viral determinants of influenza A virus host range. In: The Journal of general virology. Volume 95, Pt 6 June 2014, ISSN  1465-2099 , pp. 1193-1210, doi : 10.1099 / vir.0.062836-0 , PMID 24584475 .
  5. ^ WG Dundon: Variability among the neuraminidase, non-structural 1 and PB1-F2 proteins in the influenza A virus genome. In: Virus genes. Volume 44, Number 3, June 2012, ISSN  1572-994X , pp. 363-373, doi : 10.1007 / s11262-012-0714-0 , PMID 22261818 .