Weichbrodt, Conrad

[["dc.bibliographiccitation.firstpage","9546"],["dc.bibliographiccitation.issue","20"],["dc.bibliographiccitation.journal","Physical Chemistry Chemical Physics"],["dc.bibliographiccitation.lastpage","9555"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Kozuch, Jacek"],["dc.contributor.author","Weichbrodt, Conrad"],["dc.contributor.author","Millo, Diego"],["dc.contributor.author","Giller, Karin"],["dc.contributor.author","Becker, Stefan"],["dc.contributor.author","Hildebrandt, Peter"],["dc.contributor.author","Steinem, Claudia"],["dc.date.accessioned","2017-09-07T11:46:55Z"],["dc.date.available","2017-09-07T11:46:55Z"],["dc.date.issued","2014"],["dc.description.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 via a 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 be ca. 0.0 V vs. the open circuit potential. These spectral changes were interpreted on the basis of the orientation-and distancedependent IR enhancement and indicate alterations of the inclination angle of the beta-strands as crucial molecular events, reflecting an expansion or contraction of the beta-barrel pore. These protein structural changes that do not confirm nor exclude the reorientation of the alpha-helix are either directly induced by the electric field or a consequence of a potential-dependent repulsion or attraction of the bilayer."],["dc.identifier.doi","10.1039/c4cp00167b"],["dc.identifier.gro","3142210"],["dc.identifier.isi","000335818600039"],["dc.identifier.pmid","24728177"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5754"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1463-9084"],["dc.relation.issn","1463-9076"],["dc.title","Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1223"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1234"],["dc.bibliographiccitation.volume","111"],["dc.contributor.author","Briones, Rodolfo"],["dc.contributor.author","Weichbrodt, Conrad"],["dc.contributor.author","Paltrinieri, Licia"],["dc.contributor.author","Mey, Ingo"],["dc.contributor.author","Villinger, Saskia"],["dc.contributor.author","Giller, Karin"],["dc.contributor.author","Lange, Adam"],["dc.contributor.author","Zweckstetter, Markus"],["dc.contributor.author","Griesinger, Christian"],["dc.contributor.author","Becker, Stefan"],["dc.contributor.author","Steinem, Claudia"],["dc.contributor.author","De Groot, Bert L."],["dc.date.accessioned","2017-09-07T11:44:37Z"],["dc.date.available","2017-09-07T11:44:37Z"],["dc.date.issued","2016"],["dc.description.abstract","The voltage-dependent anion channel 1 (VDAC-1) is an important protein of the outer mitochondria! membrane that transports energy metabolites and is involved in apoptosis. The available structures of VDAC proteins show a wide beta-stranded barrel pore, with its N-terminal alpha-helix (N-alpha) bound to its interior. Electrophysiology experiments revealed that voltage, its polarity, and membrane composition modulate VDAC currents. Experiments with VDAC-1 mutants identified amino acids that regulate the gating process. However, the mechanisms for how these factors regulate VDAC-1, and which changes they trigger in the channel, are still unknown. In this study, molecular dynamics simulations and single-channel experiments of VDAC-1 show agreement for the current-voltage relationships of an \"open\" channel and they also show several subconducting transient states that are more cation selective in the simulations. We observed voltage-dependent asymmetric distortions of the VDAC-1 barrel and the displacement of particular charged amino acids. We constructed conformational models of the protein voltage response and the pore changes that consistently explain the protein conformations observed at opposite voltage polarities, either in phosphatidylethanolamine or phosphatidylcholine membranes. The submicrosecond VDAC-1 voltage response shows intrinsic structural changes that explain the role of key gating amino acids and support some of the current gating hypotheses. These voltage-dependent protein changes include asymmetric barrel distortion, its interaction with the membrane, and significant displacement of N-alpha amino acids."],["dc.identifier.doi","10.1016/j.bpj.2016.08.007"],["dc.identifier.gro","3141619"],["dc.identifier.isi","000383925700015"],["dc.identifier.pmid","27653481"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13769"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1900"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1542-0086"],["dc.relation.issn","0006-3495"],["dc.rights","CC BY-NC-ND 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-nd/4.0"],["dc.title","Voltage Dependence of Conformational Dynamics and Subconducting States of VDAC-1"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]