title: Structure of the Ebola fusion peptide in a membrane-mimetic environment and the interaction with lipid rafts.
abstract: The fusion peptide EBO(16) (GAAIGLAWIPYFGPAA) comprises the fusion domain of an internal sequence located in the envelope fusion glycoprotein (GP2) of the Ebola virus. This region interacts with the cellular membrane of the host and leads to membrane fusion. To gain insight into the mechanism of the peptide-membrane interaction and fusion, insertion of the peptide was modeled by experiments in which the tryptophan fluorescence and (1)H NMR were monitored in the presence of sodium dodecyl sulfate micelles or in the presence of detergent-resistant membrane fractions. In the presence of SDS micelles, EBO(16) undergoes a random coil-helix transition, showing a tendency to self-associate. The three-dimensional structure displays a 3(10)-helix in the central part of molecule, similar to the fusion peptides of many known membrane fusion proteins. Our results also reveal that EBO(16) can interact with detergent-resistant membrane fractions and strongly suggest that Trp-8 and Phe-12 are important for structure maintenance within the membrane bilayer. Replacement of tryptophan 8 with alanine (W8A) resulted in dramatic loss of helical structure, proving the importance of the aromatic ring in stabilizing the helix. Molecular dynamics studies of the interaction between the peptide and the target membrane also corroborated the crucial participation of these aromatic residues. The aromatic-aromatic interaction may provide a mechanism for the free energy coupling between random coil-helical transition and membrane anchoring. Our data shed light on the structural "domains" of fusion peptides and provide a clue for the development of a drug that might block the early steps of viral infection.
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ.
authors.forename: Mônica S
authors.initials: MS
authors.lastname: Freitas
authors.affiliation: Departamento de Virologia, Instituto Oswaldo Cruz, Fiocruz, 21040-360 Rio de Janeiro, RJ.
authors.forename: Luciane P
authors.initials: LP
authors.lastname: Gaspar
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo 14040-901, Ribeirão Preto, S.P., and.
authors.forename: Marcos
authors.initials: M
authors.lastname: Lorenzoni
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ.
authors.forename: Fabio C L
authors.initials: FCL
authors.lastname: Almeida
authors.affiliation: Núcleo de Produtos Naturais, Laboratório de Analise e Desenvolvimento de Inibidores Enzimáticos, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ, Brazil.
authors.forename: Luzineide W
authors.initials: LW
authors.lastname: Tinoco
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ.
authors.forename: Marcius S
authors.initials: MS
authors.lastname: Almeida
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ.
authors.forename: Lenize F
authors.initials: LF
authors.lastname: Maia
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo 14040-901, Ribeirão Preto, S.P., and.
authors.forename: Léo
authors.initials: L
authors.lastname: Degrève
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Valente
authors.affiliation: Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ. Electronic address: jerson@bioqmed.ufrj.br.
authors.forename: Jerson L
authors.initials: JL
authors.lastname: Silva
mesh_terms: D000595:Amino Acid Sequence; D029043:Ebolavirus / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D021962:Membrane Microdomains / Q000737:chemistry*; D008823:Micelles; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014760:Viral Fusion Proteins / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D008823:Micelles; D014760:Viral Fusion Proteins