title: Self-Assembly of the Toll-Like Receptor Agonist Macrophage-Activating Lipopeptide MALP-2 and of Its Constituent Peptide.
abstract: The self-assembly of the macrophage-activating lipopeptide MALP-2 in aqueous solution has been investigated and is compared to that of the constituent peptide GNNDESNISFKEK. MALP-2 is a toll-like receptor agonist lipopeptide with diverse potential biomedical applications and its self-assembly has not previously been examined. It is found to self-assemble, above a critical aggregation concentration (cac), into remarkable "fibre raft" structures, based on lateral aggregation of β-sheet based bilayer tapes. Peptide GNNDESNISFKEK also forms β-sheet structures above a cac, although the morphology is distinct, comprising highly extended and twisted tape structures. A detailed insight into the molecular packing within the MALP-2 raft and GNNDESNISFKEK nanotape structures is obtained through X-ray diffraction and small-angle X-ray scattering. These results point to the significant influence of the attached lipid chains on the self-assembly motif, which lead to the raft structure for the lipopeptide assemblies.
authors.affiliation: School of Chemistry, Pharmacy and Food Biosciences, University of Reading , Whiteknights, Reading, RG6 6AD, United Kingdom.
authors.forename: Valeria
authors.initials: V
authors.lastname: Castelletto
authors.affiliation: School of Chemistry, Pharmacy and Food Biosciences, University of Reading , Whiteknights, Reading, RG6 6AD, United Kingdom.
authors.forename: Steven
authors.initials: S
authors.lastname: Kirkham
authors.affiliation: School of Chemistry, Pharmacy and Food Biosciences, University of Reading , Whiteknights, Reading, RG6 6AD, United Kingdom.
authors.forename: Ian W
authors.initials: IW
authors.lastname: Hamley
authors.affiliation: School of Chemistry, Pharmacy and Food Biosciences, University of Reading , Whiteknights, Reading, RG6 6AD, United Kingdom.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Kowalczyk
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1D, 40237 Düsseldorf, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Rabe
authors.affiliation: Department of Applied Physics, Aalto University School of Science , P.O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: Mehedi
authors.initials: M
authors.lastname: Reza
authors.affiliation: Department of Applied Physics, Aalto University School of Science , P.O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Ruokolainen
mesh_terms: D000595:Amino Acid Sequence; D055666:Lipopeptides / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D055503:Protein Multimerization; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
chemical_list: D055666:Lipopeptides; D010446:Peptide Fragments; C106335:macrophage stimulatory lipopeptide 2