Lateral voltage as a new input for artificial lipid bilayer systems

2021 ◽  
Author(s):  
Teng Ma ◽  
Madoka Sato ◽  
Maki Komiya ◽  
Kensaku Kanomata ◽  
Takaya Watanabe ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Transmembrane Voltage

In this work, we propose lateral voltage as a new input for use in artificial lipid bilayer systems in addition to the commonly used transmembrane voltage. To apply a lateral...

scholarly journals Water Pores in Planar Lipid Bilayers at Fast and Slow Rise of Transmembrane Voltage

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 263
Author(s):  
Alenka Maček Lebar ◽  
Damijan Miklavčič ◽  
Malgorzata Kotulska ◽  
Peter Kramar
Keyword(s):  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Barrier Properties ◽  
Model Systems ◽  
Planar Lipid Bilayer ◽  
Planar Lipid Bilayers ◽  
Membrane Rupture ◽  
Transmembrane Voltage ◽  
Slow Rise ◽  
The Moment

Basic understanding of the barrier properties of biological membranes can be obtained by studying model systems, such as planar lipid bilayers. Here, we study water pores in planar lipid bilayers in the presence of transmembrane voltage. Planar lipid bilayers were exposed to fast and slow linearly increasing voltage and current signals. We measured the capacitance, breakdown voltage, and rupture time of planar lipid bilayers composed of 1-pamitoyl 2-oleoyl phosphatidylcholine (POPC), 1-pamitoyl 2-oleoyl phosphatidylserine (POPS), and a mixture of both lipids in a 1:1 ratio. Based on the measurements, we evaluated the change in the capacitance of the planar lipid bilayer corresponding to water pores, the radius of water pores at membrane rupture, and the fraction of the area of the planar lipid bilayer occupied by water pores.planar lipid bilayer capacitance, which corresponds to water pores, water pore radius at the membrane rupture, and a fraction of the planar lipid bilayer area occupied by water pores. The estimated pore radii determining the rupture of the planar lipid bilayer upon fast build-up of transmembrane voltage are 0.101 nm, 0.110 nm, and 0.106 nm for membranes composed of POPC, POPS, and POPC:POPS, respectively. The fraction of the surface occupied by water pores at the moment of rupture of the planar lipid bilayer The fraction of an area that is occupied by water pores at the moment of planar lipid bilayer rupture is in the range of 0.1–1.8%.

scholarly journals Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Doreen Matthies ◽  
Chanhyung Bae ◽  
Gilman ES Toombes ◽  
Tara Fox ◽  
Alberto Bartesaghi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Bilayer ◽  
Single Particle ◽  
Transmembrane Domain ◽  
X Ray ◽  
Kv Channels ◽  
Cryo Electron Microscopy ◽  
Transmembrane Voltage ◽  
Structural Mechanisms ◽  
Lipid Nanodiscs

Voltage-activated potassium (Kv) channels open to conduct K+ ions in response to membrane depolarization, and subsequently enter non-conducting states through distinct mechanisms of inactivation. X-ray structures of detergent-solubilized Kv channels appear to have captured an open state even though a non-conducting C-type inactivated state would predominate in membranes in the absence of a transmembrane voltage. However, structures for a voltage-activated ion channel in a lipid bilayer environment have not yet been reported. Here we report the structure of the Kv1.2–2.1 paddle chimera channel reconstituted into lipid nanodiscs using single-particle cryo-electron microscopy. At a resolution of ~3 Å for the cytosolic domain and ~4 Å for the transmembrane domain, the structure determined in nanodiscs is similar to the previously determined X-ray structure. Our findings show that large differences in structure between detergent and lipid bilayer environments are unlikely, and enable us to propose possible structural mechanisms for C-type inactivation.

Nano-pore Lipid Bilayer Formed by Self-spreading Method

2019 ◽  
Vol 139 (10) ◽  
pp. 1146-1152
Author(s):  
Zugui Peng ◽  
Kenta Shimba ◽  
Yoshitaka Miyamoto ◽  
Tohru Yagi
Keyword(s):  
Lipid Bilayer

Spotting Differences in Molecular Dynamic Simulations of Influenza A M2 Protein-Ligand Complexes by Varying M2 construct, Lipid Bilayer and Force Field

2019 ◽  
Author(s):  
Dimitrios Kolokouris ◽  
Iris Kalenderoglou ◽  
Panagiotis Lagarias ◽  
Antonios Kolocouris
Keyword(s):  
Molecular Dynamic ◽  
Lipid Bilayer ◽  
Influenza A ◽  
Md Simulations ◽  
Membrane Curvature ◽  
Buffer Size ◽  
M2 Protein ◽  
Dynamic Simulations ◽  
Amphipathic Helices ◽  
Drug Protein Binding

<p>We studied by molecular dynamic (MD) simulations systems including the inward<sub>closed</sub> state of influenza A M2 protein in complex with aminoadamantane drugs in membrane bilayers. We varied the M2 construct and performed MD simulations in M2TM or M2TM with amphipathic helices (M2AH). We also varied the lipid bilayer by changing either the lipid, DMPC or POPC, POPE or POPC/cholesterol (chol), or the lipids buffer size, 10x10 Å<sup>2 </sup>or 20x20 Å<sup>2</sup>. We aimed to suggest optimal system conditions for the computational description of this ion channel and related systems. Measures performed include quantities that are available experimentally and include: (a) the position of ligand, waters and chlorine anion inside the M2 pore, (b) the passage of waters from the outward Val27 gate of M2 S31N in complex with an aminoadamantane-aryl head blocker, (c) M2 orientation, (d) the AHs conformation and structure which is affected from interactions with lipids and chol and is important for membrane curvature and virus budding. In several cases we tested OPLS2005, which is routinely applied to describe drug-protein binding, and CHARMM36 which describes reliably protein conformation. We found that for the description of the ligands position inside the M2 pore, a 10x10 Å<sup>2</sup> lipids buffer in DMPC is needed when M2TM is used but 20x20 Å<sup>2</sup> lipids buffer of the softer POPC; when M2AH is used all 10x10 Å<sup>2</sup> lipid buffers with any of the tested lipids can be used. For the passage of waters at least M2AH with a 10x10 Å<sup>2</sup> lipid buffer is needed. The folding conformation of AHs which is defined from hydrogen bonding interactions with the bilayer and the complex with chol is described well with a 10x10 Å<sup>2</sup> lipids buffer and CHARMM36. </p>

scholarly journals Transmembrane signal transduction by cofactor transport

2021 ◽  
Author(s):  
Istvan Kocsis ◽  
Yudi Ding ◽  
Nicholas H. Williams ◽  
Christopher A. Hunter
Keyword(s):  
Signal Transduction ◽  
Lipid Bilayer ◽  
Metal Ion ◽  
Bilayer Membrane ◽  
Ester Hydrolysis ◽  
Lipid Bilayer Membrane ◽  
Metal Ion Cofactors

Synthetic transducers transport externally added metal ion cofactors across the lipid bilayer membrane of vesicles to trigger catalysis of ester hydrolysis in the inner compartment. Signal transduction activity is modulated by hydrazone formation.

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