title: Effect of E1(64-81) hepatitis G peptide on the in vitro interaction of HIV-1 fusion peptide with membrane models.
abstract: One way to gain information about the fusogenic potential of virus-derived synthetic peptides is to examine their interfacial properties and subsequently to study them in monolayers and bilayers. Here, we characterize the physicochemical surface properties of the peptide E1(64-81), whose sequence is AQLVGELGSLYGPLSVSA. This peptide is derived from the E1 structural protein of GBV-C/HGV which was previously shown to inhibit leakage of vesicular contents caused by the HIV-1 fusion peptide (HIV-1 FP). Mixed isotherms of E1(64-81) and HIV-1 FP were obtained and their Brewster angle microscopy (BAM) and atomic force microscopy (AFM) images showed that the peptide mixture forms a different structure that is not present in the pure peptide images. Studies with lipid monolayers (1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DMPG) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DPPG)) show that both peptides interact with all the lipids assayed but the effect that HIV-1 FP has on the monolayers is reduced in the presence of E1(64-81). Moreover, differential scanning calorimetry (DSC) experiments show the capacity of HIV-1 FP to modify the properties of the bilayer structure and the capacity of E1(64-81) to inhibit these modifications. Our results indicate that E1(64-81) interacts with HIV-1 FP to form a new structure, and that this may be the cause of the previously observed inhibition of the activity of HIV-1 FP by E1(64-81).
authors.affiliation: Physical Chemistry Department, Faculty of Pharmacy, University of Barcelona, CSIC-Associated Unit: Peptides and Proteins: Physicochemical Studies, IN2UB Av. Joan XXIII s/n, 08028 Barcelona, Spain. mjsanchez@ub.edu
authors.forename: Maria Jesús
authors.initials: MJ
authors.lastname: Sánchez-Martín
authors.forename: M Antònia
authors.initials: MA
authors.lastname: Busquets
authors.forename: Victoria
authors.initials: V
authors.lastname: Girona
authors.forename: Isabel
authors.initials: I
authors.lastname: Haro
authors.forename: M Asunción
authors.initials: MA
authors.lastname: Alsina
authors.forename: Montserrat
authors.initials: M
authors.lastname: Pujol
mesh_terms: D000327:Adsorption; D001703:Biophysics / Q000379:methods; D002152:Calorimetry, Differential Scanning / Q000379:methods; D002462:Cell Membrane / Q000821:virology; D002942:Circular Dichroism; D029407:GB virus C / Q000378:metabolism*; D015497:HIV-1 / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods; D010455:Peptides / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D013499:Surface Properties; D014759:Viral Envelope Proteins / Q000737:chemistry*; D014760:Viral Fusion Proteins / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010455:Peptides; D010715:Phosphatidylglycerols; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; C030345:1,2-dipalmitoylphosphatidylglycerol