title: γ-Hemolysin oligomeric structure and effect of its formation on supported lipid bilayers: an AFM investigation.
abstract: γ-Hemolysins are bicomponent β-barrel pore forming toxins produced by Staphylococcus aureus as water-soluble monomers, which assemble into oligomeric pores on the surface of lipid bilayers. Here, after investigating the oligomeric structure of γ-hemolysins on supported lipid bilayers (SLBs) by atomic force microscopy (AFM), we studied the effect produced by this toxin on the structure of SLBs. We found that oligomeric structures with different number of monomers can assemble on the lipid bilayer being the octameric form the stablest one. Moreover, in this membrane model we found that γ-hemolysins can form clusters of oligomers inducing a curvature in the lipid bilayer, which could probably enhance the aggressiveness of these toxins at high concentrations.
authors.affiliation: Centro S3, CNR-Istituto di Nanoscienze, Via Campi 213/A, 41125 Modena, Italy. andrea.alessandrini@unimore.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Alessandrini
authors.forename: Gabriella
authors.initials: G
authors.lastname: Viero
authors.forename: Mauro
authors.initials: M
authors.lastname: Dalla Serra
authors.forename: Gilles
authors.initials: G
authors.lastname: Prévost
authors.forename: Paolo
authors.initials: P
authors.lastname: Facci
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D001703:Biophysics / Q000379:methods; D018360:Crystallography, X-Ray / Q000379:methods; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D006460:Hemolysin Proteins / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods*; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013211:Staphylococcus aureus / Q000378:metabolism*; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes