title: Interfacial properties of a synthetic peptide derived from hepatitis G virus E2 protein: interaction with lipid monolayers.
abstract: A useful approach to get information about the potential fusogenic ability of virus synthetic peptides is the study of its interfacial properties and subsequent study in mono- and bilayers. In this work, we have characterized by means of physicochemical tools (i.e. compression isotherms and surface activity) the sequence 267-284, LLGTEVSEVLGGAGLTGG, derived from the E2 structural protein of HGV/GBV-C. The adsorption of the peptide at the air/water interface was monitored by following the increase in surface pressure as a function of time at two different pH values: 5 and 7. Parameters such as surface excess or molecular area were calculated from the equation of Gibbs. The peptide showed a tendency to migrate to the surface of a saline-buffered solution. It formed stable monolayers at the air/water interface giving a compression isotherm with a shape consistent with that of some alpha-helical peptide conformations. Brewster angle microscopy (BAM) showed that through compression the peptide formed multilayers. The studies with lipid monolayers (DPMC, DMPC/DMPG, and DMPC/DMTAP) showed that the peptide interacts with all the lipids assayed producing a marked disrupting effect upon them. In these effects electrostatic interactions seem to have some participation.
authors.affiliation: CSIC Associate Unity Peptides & Proteins, Physicochemical Studies, Physicochemistry Department, Faculty of Pharmacy, 08028 Barcelona, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Casas
authors.forename: Marta
authors.initials: M
authors.lastname: Espina
authors.forename: Marta
authors.initials: M
authors.lastname: Haro
authors.forename: Felix
authors.initials: F
authors.lastname: Royo
authors.forename: M Asunción
authors.initials: MA
authors.lastname: Alsina
authors.forename: Isabel
authors.initials: I
authors.lastname: Haro
authors.forename: Concepción
authors.initials: C
authors.lastname: Mestres
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D029407:GB virus C / Q000737:chemistry / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D009226:Myristates / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D010715:Phosphatidylglycerols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: C117241:1,2-dimyristoyl-3-trimethylammonium propane; D008055:Lipids; D008567:Membranes, Artificial; D009226:Myristates; D010446:Peptide Fragments; D010715:Phosphatidylglycerols; D000644:Quaternary Ammonium Compounds; D014759:Viral Envelope Proteins; C107619:glycoprotein E2, GB virus C; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine