Time-resolved electromechanical and conductive behavior of nanostructured bilayers tethered to the surface of the electrode with incorporated channel proteins and peptides.

Abstract

The influence of incorporation of mitochondrial inner membrane potassium channel, and channel-forming peptide - Gramicidin on the ion transport and electromechanical properties of model lipid membranes tethered to gold electrode was electrochemically investigated by chronoamperometric and impedance spectroscopy techniques. In the case of the potassium channel the ion transport properties were modulated with channel-specific inhibitor - ATP-Mg²⁺ complex, whereas in the case of gramicidin peptide - by replacing potassium with sodium ions. The observed two exponential current-time responses of the systems studied were interpreted in terms of ion penetration and electrostriction of tethered lipid bilayer membrane, and conclusions supported with the experiments on alkanethiol self-assembled monolayers of different alkanethiol chain lengths deposited on gold.