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