title: Transmembrane peptide NB of influenza B: a simulation, structure, and conductance study.
abstract: The putative transmembrane segment of the ion channel forming peptide NB from influenza B was synthesized by standard solid-phase peptide synthesis. Insertion into the planar lipid bilayer revealed ion channel activity with conductance levels of 20, 61, 107, and 142 pS in a 0.5 M KCl buffer solution. In addition, levels at -100 mV show conductances of 251 and 413 pS. A linear current-voltage relation reveals a voltage-independent channel formation. In methanol and in vesicles the peptide appears to adopt an alpha-helical-like structure. Computational models of alpha-helix bundles using N = 4, 5, and 6 NB peptides per bundle revealed water-filled pores after 1 ns of MD simulation in a solvated lipid bilayer. Calculated conductance values [using HOLE (Smart et al. (1997) Biophys. J. 72, 1109-1126)] of ca. 20, 60, and 90 pS, respectively, suggested that the multiple conductance levels seen experimentally must correspond to different degrees of oligomerization of the peptide to form channels.
authors.affiliation: Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K. wolfgang@bioch.ox.ac.uk
authors.forename: W B
authors.initials: WB
authors.lastname: Fischer
authors.forename: M
authors.initials: M
authors.lastname: Pitkeathly
authors.forename: B A
authors.initials: BA
authors.lastname: Wallace
authors.forename: L R
authors.initials: LR
authors.lastname: Forrest
authors.forename: G R
authors.initials: GR
authors.lastname: Smith
authors.forename: M S
authors.initials: MS
authors.lastname: Sansom
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003198:Computer Simulation; D004553:Electric Conductivity; D004558:Electric Stimulation; D009981:Influenza B virus / Q000737:chemistry* / Q000502:physiology; D007473:Ion Channels / Q000737:chemistry / Q000502:physiology; D008051:Lipid Bilayers / Q000737:chemistry; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000502:physiology; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000502:physiology; D017433:Protein Structure, Secondary; D012984:Software; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000502:physiology; D014867:Water
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers; D008562:Membrane Glycoproteins; C051094:NB glycoprotein, Influenza B virus; D010455:Peptides; D014764:Viral Proteins; D014867:Water