title: Crown ether helical peptides are preferentially inserted in lipid bilayers as a transmembrane ion channels.
abstract: Oriented circular dichroism was used to study the alignment crown ether-modified peptides. The influence of different N- and C-functionalities was assessed using at variable peptide:lipid ratios from 1:20 to 1:200. Neither the functionalities nor the concentration had any major effect on the orientation. The alignment of the 21-mer peptides was also examined with lipid membranes of different bilayer thickness. The use of synchrotron radiation as light source allowed the study of peptide:lipid molar ratios from 1:20 to 1:1000. For all conditions studied, the peptides were found to be predominantly incorporated as a transmembrane helix into the membrane, especially at low peptide concentration, but started to aggregate on the membrane surface at higher peptide:lipid ratios. The structural information on the preferred trans-bilayer alignment of the crown ether functional groups explains their ion conductivity and is useful for the further development of membrane-active nanochemotherapeutics.
authors.affiliation: Faculté des Sciences et de Génie, Département de chimie and PROTEO, Université Laval, Québec, QC, G1V 0A6, Canada.|Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany.
authors.forename: Jean-Daniel
authors.initials: JD
authors.lastname: Savoie
authors.affiliation: Faculté des Sciences et de Génie, Département de chimie and PROTEO, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Otis
authors.affiliation: Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Bürck
authors.affiliation: Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Ulrich
authors.affiliation: Faculté des Sciences et de Génie, Département de chimie and PROTEO, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: Normand
authors.initials: N
authors.lastname: Voyer
mesh_terms: D004987:Ethers / Q000737:chemistry; D007473:Ion Channels / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D004987:Ethers; D007473:Ion Channels; D008051:Lipid Bilayers; D010455:Peptides
keywords: crown ether peptides; membrane-active peptides; nanochemotherapeutics; oriented circular dichroism; synchrotron radiation