title: Ionic channel behavior of modified cyclodextrins inserted in lipid membranes.
abstract: We study the insertion and behavior of modified amphiphilic cyclodextrins in suspended bilayer lipid membranes by electrophysiological methods. We observe that our molecules build single well-defined ionic channels. The pore conductance is measured in two lipid membranes differing by their composition. These measurements reveal two distinct behaviors. In the case of thin membranes, we observe single channels, whereas in the case of thick membranes, we only detect a large number of aggregated channels. In a few experiments, we have been able to monitor the transition between the two behaviors by modifying slightly the swelling of the lipid bilayers by decane. The precise structure of the channels is yet unknown; however, we deduce from our measurements an estimation of the channel diameter.
authors.affiliation: Laboratoire Matériaux Polymères aux Interfaces, Université d'Evry Val d'Essonne, Boulevard François Mitterrand, 91025 Evry Cedex, France. laurent.bacri@physique.univ-evry.fr
authors.forename: Laurent
authors.initials: L
authors.lastname: Bacri
authors.forename: Amal
authors.initials: A
authors.lastname: Benkhaled
authors.forename: Philippe
authors.initials: P
authors.lastname: Guégan
authors.forename: Loïc
authors.initials: L
authors.lastname: Auvray
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D007473:Ion Channels; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008567:Membranes, Artificial; D008954:Models, Biological; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D003505:Cyclodextrins; D007473:Ion Channels; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D010743:Phospholipids; D047392:beta-Cyclodextrins; C024990:asolectin; C031215:betadex