title: Biophysical measurement of the balance of influenza a hemagglutinin and neuraminidase activities.
abstract: The interaction of influenza A viruses with the cell surface is controlled by the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). These two glycoproteins have opposing activities: HA is responsible for binding the host receptor (sialic acid) to allow infection, and NA is responsible for cleaving the receptor to facilitate virus release. Several studies have demonstrated that compatible levels of HA and NA activity are required for a virus to replicate efficiently. This is consequently of great interest for determining virus transmissibility. The concurrent role of these two proteins in receptor binding has never been directly measured. We demonstrate a novel biophysical approach based on bio-layer interferometry to measure the balance of the activities of these two proteins in real time. This technique measures virus binding to and release from a surface coated with either the human-like receptor analog α2,6-linked sialic acid or the avian-like receptor analog α2,3-linked sialic acid in both the presence and absence of NA inhibitors. Bio-layer interferometry measurements were also carried out to determine the effect of altering HA receptor affinity and NA stalk length on receptor binding.
authors.affiliation: From the Divisions of Virology and.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Benton
authors.affiliation: Physical Biochemistry, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Martin
authors.affiliation: From the Divisions of Virology and.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Wharton
authors.affiliation: From the Divisions of Virology and john.mccauley@nimr.mrc.ac.uk.
authors.forename: John W
authors.initials: JW
authors.lastname: McCauley
mesh_terms: D055592:Biophysical Phenomena; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry / Q000472:pathogenicity; D007251:Influenza, Human / Q000235:genetics* / Q000473:pathology / Q000821:virology; D007700:Kinetics; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000235:genetics; D009439:Neuraminidase / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D011991:Receptors, Virus / Q000737:chemistry / Q000378:metabolism
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D011991:Receptors, Virus; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid
keywords: Biophysics; Enzyme Turnover; Hemagglutinin; Influenza Virus; Kinetics; Neuraminidase; Receptor Analogs; Receptor Binding