Structure and orientation study of Ebola fusion peptide inserted in lipid membrane models.
Biochim Biophys Acta
; 1838(1 Pt B): 117-26, 2014 Jan.
Article
en En
| MEDLINE
| ID: mdl-24055820
The fusion peptide of Ebola virus comprises a highly hydrophobic sequence located downstream from the N-terminus of the glycoprotein GP2 responsible for virus-host membrane fusion. The internal fusion peptide of GP2 inserts into membranes of infected cell to mediate the viral and the host cell membrane fusion. Since the sequence length of Ebola fusion peptide is still not clear, we study in the present work the behavior of two fusion peptides of different lengths which were named EBO17 and EBO24 referring to their amino acid length. The secondary structure and orientation of both peptides in lipid model systems made of DMPC:DMPG:cholesterol:DMPE (6:2:5:3) were investigated using PMIRRAS and polarized ATR spectroscopy coupled with Brewster angle microscopy. The infrared results showed a structural flexibility of both fusion peptides which are able to transit reversibly from an α-helix to antiparallel ß-sheets. Ellipsometry results corroborate together with isotherm measurements that EBO peptides interacting with lipid monolayer highly affected the lipid organization. When interacting with a single lipid bilayer, at low peptide content, EBO peptides insert as mostly α-helices mainly perpendicular into the lipid membrane thus tend to organize the lipid acyl chains. Inserted in multilamellar vesicles at higher peptide content, EBO peptides are mostly in ß-sheet structures and induce a disorganization of the lipid chain order. In this paper, we show that the secondary structure of the Ebola fusion peptide is reversibly flexible between α-helical and ß-sheet conformations, this feature being dependent on its concentration in lipids, eventually inducing membrane fusion.
Palabras clave
ATR; BAM; Brewster angle microscopy; DMPC; DMPE; DMPG; Ebola fusion peptide; Ellipsometry; IR spectroscopy; Lipid/peptide interaction; PMIRRAS; Ri; Secondary structure; Viral fusion mechanism; attenuated total reflection spectroscopy; dimyristoyl-phosphatidylcholine; dimyristoyl-phosphatidylethanolamine; dimyristoyl-phosphatidylglycerol; lipid to peptide ratio; polarization modulation infra-red reflection absorption spectroscopy
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oligopéptidos
/
Proteínas Virales de Fusión
/
Ebolavirus
/
Membrana Dobles de Lípidos
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
2014
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Países Bajos