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

• Published in: Bioelectrochemistry (Amsterdam, Netherlands) Netherlands), 2025-04, Vol.162, p.108848, Article 108848
• Main Authors: Stefanowska, Aleksandra, Czapczyński, Michał, Koprowski, Piotr, Szewczyk, Adam, Krysiński, Paweł
• Format: Article
• Language: English
• Subjects: Dielectric Spectroscopy; Electric Conductivity; Electrodes; Electromechanical properties; Gold - chemistry; Gramicidin; Gramicidin - chemistry; Gramicidin - metabolism; Impedance spectroscopy; Lipid Bilayers - chemistry; Mitochondria; Nanostructures - chemistry; Peptides - chemistry; Potassium Channels - chemistry; Potassium Channels - metabolism; ROMK2 potassium channel; Surface Properties; Tethered bilayer lipid membrane; Time-resolved chronoamperometry
• ISSN: 1567-5394; 1878-562X; 1878-562X
• DOI: 10.1016/j.bioelechem.2024.108848

•Tethered lipid bilayers on gold with ROMK2 K+ channel or Gramicidin were studied.•The effect of channel inhibitor and potassium vs. sodium conductance was evaluated.•Chronoamperometry reveals electromechanical properties of different time constants. 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.