Conformational and Interfacial Analyses of K3A18K3 and Alamethicin in Model Membranes
Autor: | René Buchet, Achraf Kouzayha, Olivier Wattraint, Mehmet Nail Nasir, Françoise Besson, Catherine Sarazin |
---|---|
Přispěvatelé: | Génie Enzymatique et Cellulaire (GEC), Université de Technologie de Compiègne (UTC)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
Rok vydání: | 2009 |
Předmět: |
Circular dichroism
Magnetic Resonance Spectroscopy 1 2-Dipalmitoylphosphatidylcholine MESH: 1 2-Dipalmitoylphosphatidylcholine MESH: Protein Structure Secondary Peptide 02 engineering and technology MESH: Spectroscopy Fourier Transform Infrared Phase Transition Protein Structure Secondary MESH: Circular Dichroism Hydrophobic effect MESH: Dimyristoylphosphatidylcholine 03 medical and health sciences chemistry.chemical_compound Protein structure Spectroscopy Fourier Transform Infrared Monolayer MESH: Water Materials Chemistry [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry Molecular Biology/Biochemistry [q-bio.BM] Alamethicin Physical and Theoretical Chemistry 030304 developmental biology chemistry.chemical_classification 0303 health sciences MESH: Magnetic Resonance Spectroscopy Chemistry Air Circular Dichroism MESH: Alamethicin Water Membranes Artificial 021001 nanoscience & nanotechnology Surfaces Coatings and Films Peptide Conformation Crystallography MESH: Air Membrane lipids (amino acids peptides and proteins) Adsorption MESH: Adsorption MESH: Membranes Artificial MESH: Phase Transition Dimyristoylphosphatidylcholine 0210 nano-technology |
Zdroj: | The Journal of physical chemistry The Journal of physical chemistry, American Chemical Society (ACS), 2009, 113, pp.7012-7019 Journal of Physical Chemistry B Journal of Physical Chemistry B, American Chemical Society, 2009, 113 (19), pp.7012-9. ⟨10.1021/jp810539b⟩ |
ISSN: | 1520-5207 1520-6106 0022-3654 1541-5740 |
DOI: | 10.1021/jp810539b |
Popis: | International audience; The involvement of membrane-bound peptides and the influence of protein conformations in several neurodegenerative diseases lead us to analyze the interactions of model peptides with artificial membranes. Two model peptides were selected. The first one, an alanine-rich peptide, K3A18K3, was shown to be in alpha-helix structures in TFE, a membrane environment-mimicking solvent, while it was mostly beta-sheeted in aqueous buffer as revealed by infrared spectroscopy. The other, alamethicin, a natural peptide, was in a stable alpha-helix structure. To determine the role of the peptide conformation on the nature of its interactions with lipids, we compared the structure and topology of the conformational-labile peptide K3A18K3 and of the alpha-helix rigid alamethicin in both aqueous and phospholipid environments (Langmuir monolayers and multilamellar vesicles). K3A18K3 at the air-water interface showed a pressure-dependent orientation of its beta-sheets, while the alpha-helix axis of alamethicin was always parallel to the interface, as probed by polarization modulation infrared reflection absorption spectroscopy. The beta-sheeted K3A18K3 peptide was uniformly distributed into DPPC condensed domains, while the helical-alamethicin insertion distorted the DPPC condensed domains, as evidenced by Brewster angle microscopy imaging of the air/interface. The beta-sheeted K3A18K3 interacted with DMPC multilamellar vesicles via hydrophilic interactions with polar heads and the helical-alamethicin via hydrophobic interactions with alkyl chains, as shown by infrared spectroscopy and solid state NMR. Our findings are consistent with the prevailing assumption that the conformation of the peptide predetermines the mode of interaction with lipids. More precisely, helical peptides tend to be inserted via hydrophobic interactions within the hydrophobic region of membranes, while beta-sheeted peptides are predisposed to interact with polar groups and stay at the surface of lipid layers. |
Databáze: | OpenAIRE |
Externí odkaz: |