Ionic channel behavior of modified cyclodextrins inserted in lipid membranes.
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.
Bacri
Laurent
L
Laboratoire Matériaux Polymères aux Interfaces, Université d'Evry Val d'Essonne, Boulevard François Mitterrand, 91025 Evry Cedex, France. laurent.bacri@physique.univ-evry.fr
Benkhaled
Amal
A
Guégan
Philippe
P
Auvray
Loïc
L
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
D003505:Cyclodextrins; D007473:Ion Channels; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D010743:Phospholipids; D047392:beta-Cyclodextrins; C024990:asolectin; C031215:betadex