title: Core-6 fucose and the oligomerization of the 1918 pandemic influenza viral neuraminidase.
abstract: The 1918 H1N1 influenza virus was responsible for one of the most deadly pandemics in human history. Yet to date, the structure component responsible for its virulence is still a mystery. In order to search for such a component, the neuraminidase (NA) antigen of the virus was expressed, which led to the discovery of an active form (tetramer) and an inactive form (dimer and monomer) of the protein due to different glycosylation. In this report, the N-glycans from both forms were released and characterized by mass spectrometry. It was found that the glycans from the active form had 26% core-6 fucosylated, while the glycans from the inactive form had 82% core-6 fucosylated. Even more surprisingly, the stalk region of the active form was almost completely devoid of core-6-linked fucose. These findings were further supported by the results obtained from in vitro incorporation of azido fucose and (3)H-labeled fucose using core-6 fucosyltransferase, FUT8. In addition, the incorporation of fucose did not change the enzymatic activity of the active form, implying that core-6 fucose is not directly involved in the enzymatic activity. It is postulated that core-6 fucose prohibits the oligomerization and subsequent activation of the enzyme.
authors.affiliation: Bio-Techne Inc., 614 McKinley Place NE, Minneapolis, MN 55413, USA. Electronic address: Leon.wu@bio-techne.com.
authors.forename: Zhengliang L
authors.initials: ZL
authors.lastname: Wu
authors.affiliation: Gregg Hall, UNH Glycomics Center, University of New Hampshire, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Bio-Techne Inc., 614 McKinley Place NE, Minneapolis, MN 55413, USA.
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Ethen
authors.affiliation: Gregg Hall, UNH Glycomics Center, University of New Hampshire, USA. Electronic address: Vernon.Reinhold@unh.edu.
authors.forename: Vernon
authors.initials: V
authors.lastname: N Reinhold
mesh_terms: D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D004789:Enzyme Activation; D005643:Fucose / Q000032:analysis*; D006031:Glycosylation; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry / Q000201:enzymology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000737:chemistry*; D011134:Polysaccharides / Q000032:analysis; D055503:Protein Multimerization
chemical_list: D011134:Polysaccharides; D005643:Fucose; D009439:Neuraminidase
keywords: Carbohydrate interaction; Click chemistry; Core fucose; Fucosyltransferase; Influenza viral neuraminidase; N-glycan