Impedance spectroscopy of OmpF porin reconstituted into a mercury-supported lipid bilayer.
The channel-forming protein OmpF porin was incorporated in a biomimetic membrane consisting of a lipid bilayer tethered to a mercury electrode via a thiolipid, and it was investigated in aqueous KCl by electrochemical impedance spectroscopy. The impedance spectra, recorded from 1 x 10(-2) to 1 x 10(5) Hz over a potential range of 0.7 V, were fitted to an equivalent circuit consisting of four RC meshes. The dependence of the resulting circuit elements upon the applied potential was interpreted on the basis of a general approximate approach based on a model of the electrified interphase and on the kinetics of the translocation of potassium and chloride ions across the lipid bilayer, assisted by the OmpF porin.
Becucci
Lucia
L
Department of Chemistry, Florence University, Via della Lastruccia 3, 50019 Sesto Fiorentino (Firenze), Italy.
Moncelli
Maria Rosa
MR
Guidelli
Rolando
R
D007700:Kinetics; D008051:Lipid Bilayers; D008628:Mercury / Q000737:chemistry*; D018272:Porins / Q000737:chemistry*
D008051:Lipid Bilayers; C109237:OmpF protein; D018272:Porins; D008628:Mercury