title: Membrane permeabilization of the African horse sickness virus VP5 protein is mediated by two N-terminal amphipathic α-helices.
abstract: The VP5 outer capsid protein of African horse sickness virus (AHSV) is cytotoxic when expressed in Spodoptera frugiperda (Sf-9) cells. Secondary structure analysis of the VP5 amino acid sequence of AHSV-9 identified two N-terminal amphipathic α-helices within the first 43 amino acids. Baculovirus expression of N- and C-terminal truncated VP5 proteins in Sf-9 cells indicated that the N-terminal 43 amino acids correlated with low levels of protein expression and with increased membrane permeabilization and cytotoxicity. Exogenous addition of chemically synthesized VP5 peptides indicated that both N-terminal amphipathic α-helices are required for membrane permeabilization of Sf-9 cells. These findings suggest that AHSV VP5 is a membrane-destabilizing protein.
authors.affiliation: Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa.
authors.forename: Liesel
authors.initials: L
authors.lastname: Stassen
authors.forename: Henk
authors.initials: H
authors.lastname: Huismans
authors.forename: Jacques
authors.initials: J
authors.lastname: Theron
mesh_terms: D000356:African Horse Sickness Virus / Q000472:pathogenicity*; D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002463:Cell Membrane Permeability; D017433:Protein Structure, Secondary; D018411:Spodoptera / Q000821:virology; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D036022:Capsid Proteins; C442560:VP5 protein, African horse sickness virus; D037521:Virulence Factors