title: SARS-CoV fusion peptides induce membrane surface ordering and curvature.
abstract: Viral membrane fusion is an orchestrated process triggered by membrane-anchored viral fusion glycoproteins. The S2 subunit of the spike glycoprotein from severe acute respiratory syndrome (SARS) coronavirus (CoV) contains internal domains called fusion peptides (FP) that play essential roles in virus entry. Although membrane fusion has been broadly studied, there are still major gaps in the molecular details of lipid rearrangements in the bilayer during fusion peptide-membrane interactions. Here we employed differential scanning calorimetry (DSC) and electron spin resonance (ESR) to gather information on the membrane fusion mechanism promoted by two putative SARS FPs. DSC data showed the peptides strongly perturb the structural integrity of anionic vesicles and support the hypothesis that the peptides generate opposing curvature stresses on phosphatidylethanolamine membranes. ESR showed that both FPs increase lipid packing and head group ordering as well as reduce the intramembrane water content for anionic membranes. Therefore, bending moment in the bilayer could be generated, promoting negative curvature. The significance of the ordering effect, membrane dehydration, changes in the curvature properties and the possible role of negatively charged phospholipids in helping to overcome the high kinetic barrier involved in the different stages of the SARS-CoV-mediated membrane fusion are discussed.
authors.affiliation: Grupo de Biofísica Molecular Sérgio Mascarenhas, Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense, 400, Centro, São Carlos, SP, Brazil.|Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil.
authors.forename: Luis G M
authors.initials: LG
authors.lastname: Basso
authors.affiliation: Faculdade de Ciências e Engenharia, UNESP - Univ Estadual Paulista, Campus de Tupã. Rua Domingos da Costa Lopes, 780, 17602-496, Tupã, SP, Brazil.
authors.forename: Eduardo F
authors.initials: EF
authors.lastname: Vicente
authors.affiliation: Departamento de Bioquímica e Tecnologia Química, Instituto de Química, UNESP - Univ Estadual Paulista. Rua Prof. Franscisco Degni, 55, 14800-900, Araraquara, SP, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Crusca
authors.affiliation: Departamento de Bioquímica e Tecnologia Química, Instituto de Química, UNESP - Univ Estadual Paulista. Rua Prof. Franscisco Degni, 55, 14800-900, Araraquara, SP, Brazil.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Cilli
authors.affiliation: Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Costa-Filho
mesh_terms: D002152:Calorimetry, Differential Scanning; D002462:Cell Membrane / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008561:Membrane Fusion; D010455:Peptides / Q000737:chemistry; D045473:Severe acute respiratory syndrome-related coronavirus / Q000737:chemistry*; D013816:Thermodynamics; D014760:Viral Fusion Proteins / Q000737:chemistry*; D053586:Virus Internalization
chemical_list: D010455:Peptides; D014760:Viral Fusion Proteins