title: Self-assembly of three bacterially-derived bioactive lipopeptides.
abstract: The self-assembly in aqueous solution of three lipopeptides obtained from Bacillus subtilis has been investigated. The lipopeptides surfactin, plipastatin and mycosubtilin contain distinct cyclic peptide headgroups as well as differences in alkyl chain length, branching and chain length distribution. Cryogenic transmission electron microscopy and X-ray scattering reveal that surfactin and plipastatin aggregate into 2 nm-radius spherical micelles, whereas in complete contrast mycosubtilin self-assembles into extended nanotapes based on bilayer ordering of the lipopeptides. Circular dichroism and FTIR spectroscopy indicate the presence of turn structures in the cyclic peptide headgroup. The unexpected distinct mode of self-assembly of mycosubtilin compared to the other two lipopeptides is ascribed to differences in the surfactant packing parameter. This in turn is due to specific features of the conformation of the peptide headgroup and alkyl chain branching.
authors.affiliation: School of Chemistry, Pharmacy and Food Biosciences, University of Reading, Whiteknights, Reading, RG6 6AD, UK. E-mail: I.W.Hamley@reading.ac.uk
authors.forename: Ian W
authors.initials: IW
authors.lastname: Hamley
authors.forename: Ashkan
authors.initials: A
authors.lastname: Dehsorkhi
authors.forename: Paula
authors.initials: P
authors.lastname: Jauregi
authors.forename: Jani
authors.initials: J
authors.lastname: Seitsonen
authors.forename: Janne
authors.initials: J
authors.lastname: Ruokolainen
authors.forename: François
authors.initials: F
authors.lastname: Coutte
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Chataigné
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
mesh_terms: D001412:Bacillus subtilis; D020285:Cryoelectron Microscopy; D005227:Fatty Acids / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D055666:Lipopeptides / Q000737:chemistry*; D008074:Lipoproteins / Q000737:chemistry; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D009842:Oligopeptides / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D005227:Fatty Acids; D008051:Lipid Bilayers; D055666:Lipopeptides; D008074:Lipoproteins; D008823:Micelles; D009842:Oligopeptides; D010456:Peptides, Cyclic; C049901:plipastatin; C012448:mycosubtiline; C009365:surfactin peptide