Please use this identifier to cite or link to this item:
Main Title: Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy
Author(s): Kozuch, Jacek
Weichbrodt, Conrad
Millo, Diego
Giller, Karin
Becker, Stefan
Hildebrandt, Peter
Steinem, Claudia
Type: Article
Language Code: en
Abstract: The voltage-dependent anion channel (VDAC) is a transmembrane protein that regulates the transfer of metabolites between the cytosol and the mitochondrium. Opening and partial closing of the channel is known to be driven by the transmembrane potential viaa mechanism that is not fully understood. In this work, we employed a spectroelectrochemical approach to probe the voltage-induced molecular structure changes of human VDAC1 (hVDAC1) embedded in a tethered bilayer lipid membrane on a nanostructured Au electrode. The model membrane consisted of a mixed self-assembled monolayer of 6-mercaptohexanol and (cholesterylpolyethylenoxy)thiol, followed by the deposition of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine vesicles including hVDAC1. The stepwise assembly of the model membrane and the incorporation of hVDAC1 were monitored by surface enhanced infrared absorption and electrochemical impedance spectroscopy. Difference spectra allowed for identifying the spectral changes which may be associated with the transition from the open to the “closed” states by shifting the potential above or below the transmembrane potential determined to beca.0.0 Vvs.the open circuit potential. These spectral changes were interpreted on the basis of the orientation- and distance-dependent IR enhancement and indicate alterations of the inclination angle of the β-strands as crucial molecular events, reflecting an expansion or contraction of the β-barrel pore. These protein structural changes that do not confirm nor exclude the reorientation of the α-helix are either directly induced by the electric field or a consequence of a potential-dependent repulsion or attraction of the bilayer.
Issue Date: 2014
Date Available: 23-Jun-2016
DDC Class: 540 Chemie und zugeordnete Wissenschaften
Sponsor/Funder: DFG, EXC 314, Unifying Concepts in Catalysis
DFG, SFB 803, Funktionalität kontrolliert durch Organisation in und zwischen Membranen
Journal Title: Physical chemistry, chemical physics
Publisher: Royal Society of Chemistry
Publisher Place: Cambridge
Volume: 16
Issue: 20
Publisher DOI: 10.1039/c4cp00167b
Page Start: 9546
Page End: 9555
EISSN: 1463-9076
Notes: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
Appears in Collections:Inst. Chemie » Publications

Files in This Item:
File Description SizeFormat 
c4cp00167b.pdf1.96 MBAdobe PDFThumbnail

Items in DepositOnce are protected by copyright, with all rights reserved, unless otherwise indicated.