title: Insights on the interaction of met-enkephalin with negatively charged membranes--an infrared and solid-state NMR spectroscopic study.
abstract: Enkephalins are pentapeptides found in the human nervous system, where they are involved in the relief of pain. The interaction of these neuropeptides with the nerve cell membranes would be a key-step in the receptor binding. We have used both Fourier-transform infrared and solid-state NMR spectroscopies to shed light on the interactions responsible for the association of enkephalins with negatively charged membranes. More specifically, we have investigated the interaction of methionine-enkephalin (Menk) with DMPG and DMPS vesicles. Our results suggest that Menk interacts electrostatically with both model membranes via its terminal NH3+ group. However, the peptide induced the formation of elongated DMPG vesicles in the magnetic field. On the other hand, the association of Menk with DMPS bilayers was concentration-dependent and disrupted the membrane at high peptide concentrations. The different effect of methionine-enkephalin with the two types of anionic membranes is most likely related to the different fluidity of these systems.
authors.affiliation: Département de Chimie, Centre de Recherche en Sciences et Ingénierie des Macromolécules (CERSIM), Université Laval, Québec, Qué., Canada G1K 7P4.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Marcotte
authors.forename: Marise
authors.initials: M
authors.lastname: Ouellet
authors.forename: Michèle
authors.initials: M
authors.lastname: Auger
mesh_terms: D000838:Anions; D003903:Deuterium; D004574:Electromagnetic Fields; D004744:Enkephalin, Methionine / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008823:Micelles; D010715:Phosphatidylglycerols / Q000737:chemistry; D010759:Phosphorus Isotopes; D011485:Protein Binding; D055672:Static Electricity; D013696:Temperature; D014494:Unithiol / Q000737:chemistry
chemical_list: D000838:Anions; D008051:Lipid Bilayers; D008565:Membrane Proteins; D008823:Micelles; D010715:Phosphatidylglycerols; D010759:Phosphorus Isotopes; D014494:Unithiol; D004744:Enkephalin, Methionine; D003903:Deuterium; C002773:dimyristoylphosphatidylglycerol