title: Insertion of a coiled-coil peptide from influenza virus hemagglutinin into membranes.
abstract: The trimeric protein hemagglutinin (HA) of the influenza viral envelope is essential for cell entry. To investigate the interaction of HA with membranes, two 40-residue, cysteine-substituted peptides comprising the loop region and the first part of the coiled-coil stem were synthesized and modified with a nitroxide spin label. Electron paramagnetic resonance analysis revealed that the peptide inserts reversibly into phospholipid vesicles under endosomal pH conditions. This result suggests that some or all of the long coiled-coil trimer of HA may insert into membranes, which could bring the viral and cell membranes closer together and facilitate fusion.
authors.affiliation: Department of Chemistry, University of California, Berkeley.
authors.forename: Y G
authors.initials: YG
authors.lastname: Yu
authors.forename: D S
authors.initials: DS
authors.lastname: King
authors.forename: Y K
authors.initials: YK
authors.lastname: Shin
mesh_terms: D000595:Amino Acid Sequence; D004578:Electron Spin Resonance Spectroscopy; D004705:Endocytosis; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000378:metabolism*; D008561:Membrane Fusion; D008969:Molecular Sequence Data; D009975:Orthomyxoviridae / Q000502:physiology; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013696:Temperature; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D008051:Lipid Bilayers; D014759:Viral Envelope Proteins