title: Active 1918 pandemic flu viral neuraminidase has distinct N-glycan profile and is resistant to trypsin digestion.
abstract: The 1918 pandemic flu virus caused one of the most deadly pandemics in human history. To search for unique structural features of the neuraminidase from this virus that might have contributed to its unusual virulence, we expressed this enzyme. The purified enzyme appeared as a monomer, a dimer and a tetramer, with only the tetramer being active and therefore biologically relevant. The monomer and the dimer could not be oligomerized into the tetramer in solution, suggesting that some unique structural features were required for oligomerization and activation. These features could be related to N-glycosylation, because the tetramer displayed different N-glycans than the monomer and the dimer. Furthermore, the tetramer was found to be resistant to trypsin digestion, which may give the virus the capability to invade tissues that are normally not infected by influenza viruses and make the virus more robust for infection.
authors.affiliation: R&D Systems, Inc., 614 Mckinley Place NE, Minneapolis, MN 55413, USA. Leon.wu@rndsystems.com
authors.forename: Zhengliang L
authors.initials: ZL
authors.lastname: Wu
authors.forename: Cheryl
authors.initials: C
authors.lastname: Ethen
authors.forename: Gregg E
authors.initials: GE
authors.lastname: Hickey
authors.forename: Weiping
authors.initials: W
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D019281:Dimerization; D004196:Disease Outbreaks / Q000266:history; D006031:Glycosylation; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry* / Q000235:genetics / Q000266:history; D049673:History, 20th Century; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000201:enzymology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000266:history / Q000821:virology*; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000737:chemistry* / Q000235:genetics / Q000266:history; D011134:Polysaccharides / Q000737:chemistry; D014357:Trypsin / Q000737:chemistry
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D011134:Polysaccharides; D009439:Neuraminidase; D014357:Trypsin