title: Probing the interaction between vesicular stomatitis virus and phosphatidylserine.
abstract: The entry of enveloped animal viruses into their host cells always depends on membrane fusion triggered by conformational changes in viral envelope glycoproteins. Vesicular stomatitis virus (VSV) infection is mediated by virus spike glycoprotein G, which induces membrane fusion between the viral envelope and the endosomal membrane at the acidic environment of this compartment. In this work, we evaluated VSV interactions with membranes of different phospholipid compositions, at neutral and acidic pH, using atomic force microscopy (AFM) operating in the force spectroscopy mode, isothermal calorimetry (ITC) and molecular dynamics simulation. We found that the binding forces differed dramatically depending on the membrane phospholipid composition, revealing a high specificity of G protein binding to membranes containing phosphatidylserine (PS). In a previous work, we showed that the sequence corresponding amino acid 164 of VSV G protein was as efficient as the virus in catalyzing membrane fusion at pH 6.0. Here, we used this sequence to explore VSV-PS interaction using ITC. We found that peptide binding to membranes was exothermic, suggesting the participation of electrostatic interactions. Peptide-membrane interaction at pH 7.5 was shown to be specific to PS and dependent on the presence of His residues in the fusion peptide. The application of the simplified continuum Gouy-Chapman theory to our system predicted a pH of 5.0 at membrane surface, suggesting that the His residues should be protonated when located close to the membrane. Molecular dynamics simulations suggested that the peptide interacts with the lipid bilayer through its N-terminal residues, especially Val(145) and His(148).
authors.affiliation: Instituto de Bioquìmica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil.
authors.forename: Fabiana A
authors.initials: FA
authors.lastname: Carneiro
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Lapido-Loureiro
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Cordo
authors.forename: Fausto
authors.initials: F
authors.lastname: Stauffer
authors.forename: Gilberto
authors.initials: G
authors.lastname: Weissmüller
authors.forename: M Lucia
authors.initials: ML
authors.lastname: Bianconi
authors.forename: Maria A
authors.initials: MA
authors.lastname: Juliano
authors.forename: Luiz
authors.initials: L
authors.lastname: Juliano
authors.forename: Paulo M
authors.initials: PM
authors.lastname: Bisch
authors.forename: Andrea T
authors.initials: AT
authors.lastname: Da Poian
authors.forename: Andrea T Da
authors.initials: AT
authors.lastname: Poian
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002151:Calorimetry; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003198:Computer Simulation; D006639:Histidine / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry; D008562:Membrane Glycoproteins / Q000378:metabolism; D018625:Microscopy, Atomic Force; D010718:Phosphatidylserines / Q000378:metabolism*; D011485:Protein Binding; D055672:Static Electricity; D013816:Thermodynamics; D014633:Valine / Q000737:chemistry; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000378:metabolism
chemical_list: D000596:Amino Acids; C028391:G protein, vesicular stomatitis virus; D008081:Liposomes; D008562:Membrane Glycoproteins; D010718:Phosphatidylserines; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; D006639:Histidine; D014633:Valine