Investigating the Function of Ion Channels in Tethered Lipid Membranes by Impedance Spectroscopy

MRS Bulletin ◽  
2005 ◽  
Vol 30 (3) ◽  
pp. 207-210 ◽  
Author(s):  
Samuel Terrettaz ◽  
Horst Vogel
Keyword(s):  
Ion Channels ◽  
Impedance Spectroscopy ◽  
Ligand Binding ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Gold Electrodes ◽  
Channel Activity ◽  
Electrophysiological Measurements ◽  
Supported Lipid Membranes ◽  
Specific Ligand

AbstractThe function of biologically important ion channels can be measured in supported lipid membranes by impedance spectroscopy. This approach offers substantial advantages over traditional electrophysiological measurements. In this article, we present an overview of the field, with a special emphasis on the reconstitution of ion channels in lipid bilayers tethered to gold electrodes and the modulation of their channel activity by specific ligand binding.

Making lipid membranes even tougher

2007 ◽  
Vol 22 (8) ◽  
pp. 2189-2194 ◽  
Author(s):  
Jognandan Prashar ◽  
Phillip Sharp ◽  
Mathew Scarffe ◽  
Bruce Cornell
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Room Temperature ◽  
Materials Science ◽  
Lipid Phase ◽  
Molecular Sensing ◽  
Long Term Storage ◽  
Supported Lipid Membranes ◽  
Term Storage

Biosensors based on lipid membranes promise an inexpensive and versatile platform for application in many fields of molecular sensing. An extensive review of the applications for tethered membranes was reported in the July 2006 MRS Bulletin [A.N. Parikh and J.T. Groves, Materials science of supported lipid membranes. MRS Bull.31(8), 507 (2006)]. The commercial use to which tethered lipid membranes have been applied has been limited by their stability under long-term storage. This report describes a novel membrane construct that is stable at room temperature for months, eliminates the mobile lipid phase present in lipid bilayers, and is robust against detergents under conditions that would destroy a lipid bilayer.

Channels formed with a mutant prion protein PrP(82-146) homologous to a 7-kDa fragment in diseased brain of GSS patients

2003 ◽  
Vol 285 (4) ◽  
pp. C862-C872 ◽  
Author(s):  
Randa Bahadi ◽  
Peter V. Farrelly ◽  
Bronwyn L. Kenna ◽  
Joseph I. Kourie ◽  
Fabrizio Tagliavini ◽  
...  
Keyword(s):  
Ion Channels ◽  
Prion Protein ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Amyloid Fibrils ◽  
Time Dependent ◽  
Cation Channels ◽  
Wild Type ◽  
Fast Kinetics ◽  
Neuronal Membranes

A major prion protein (PrP) mutant that forms amyloid fibrils in the diseased brain of patients with Gerstmann-Sträussler-Scheinker syndrome (GSS) is a fragment of 7 kDa spanning from residues 81-82 to 144-153 of PrP. Analysis of ionic membrane currents, recorded with a libid bilayer technique, revealed that the wild-type fragment PrP(82-146) WT and the partially scrambled PrP(82-146) (127-146) SC are capable of forming heterogenous ion channels that are similar to those channels formed with PrP(106-126). In contrast, PrP(82-146) peptides in which the region from residue 106 to 126 had been scrambled (SC) showed a reduction in interaction with lipid membranes and did not form channels. The PrP(82-146) WT- and PrP(82-146) (127-146) SC-formed cation channels with fast kinetics are Cu2+ sensitive and rifampicin (RIF) insensitive, whereas the time-dependent inactivating channels formed by these same peptides are both Cu2+ and RIF insensitive. The presence of RIF in the solution before the addition of PrP(82-146) WT or PrP(82-146) (127-146) SC affected their incorporation into the lipid bilayers. PrP(82-146) WT and PrP(82-146) (127-146) SC fast cation channels formed in the presence of RIF appeared in an electrically semisilent state or an inactivated state. Increasing [Cd2+] cis enhanced the incorporation of PrP(82-146) WT and PrP(82-146) (127-146) SC channels formed in the presence of RIF. We conclude that the major PrP mutant fragment in the diseased brain of GSS patients is prone to form channels in neuronal membranes, causing their dysfunction. We propose that Cd2+ may accentuate the neurotoxicity of this channel-forming PrP fragment by enhancing its incorporation into the membrane.

Microcavity-Supported Lipid Membranes: Versatile Platforms for Building Asymmetric Lipid Bilayers and for Protein Recognition

2019 ◽  
Vol 2 (8) ◽  
pp. 3404-3417 ◽  
Author(s):  
Guilherme B. Berselli ◽  
Nirod Kumar Sarangi ◽  
Sivaramakrishnan Ramadurai ◽  
Paul V. Murphy ◽  
Tia E. Keyes
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Protein Recognition ◽  
Supported Lipid Membranes

scholarly journals Study of Resveratrol’s Interaction with Planar Lipid Models: Insights into Its Location in Lipid Bilayers

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 132 ◽  
Author(s):  
Daniela Meleleo
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Fruits And Vegetables ◽  
Water Solubility ◽  
Membrane Lipids ◽  
Biophysical Parameters ◽  
Beneficial Effects ◽  
Wide Range ◽  
Aging Properties ◽  
Electrophysiological Measurements

Resveratrol, a polyphenolic molecule found in edible fruits and vegetables, shows a wide range of beneficial effects on human health, including anti-microbial, anti-inflammatory, anti-cancer, and anti-aging properties. Due to its poor water solubility and high liposome-water partition coefficient, the biomembrane seems to be the main target of resveratrol, although the mode of interaction with membrane lipids and its location within the cell membrane are still unclear. In this study, using electrophysiological measurements, we study the interaction of resveratrol with planar lipid membranes (PLMs) of different composition. We found that resveratrol incorporates into palmitoyl-oleoyl-phosphatidylcholine (POPC) and POPC:Ch PLMs and forms conductive units unlike those found in dioleoyl-phosphatidylserine (DOPS):dioleoyl-phosphatidylethanolamine (DOPE) PLMs. The variation of the biophysical parameters of PLMs in the presence of resveratrol provides information on its location within a lipid double layer, thus contributing to an understanding of its mechanism of action.

scholarly journals Direct proof of spontaneous translocation of lipid-covered hydrophobic nanoparticles through a phospholipid bilayer

2016 ◽  
Vol 2 (11) ◽  
pp. e1600261 ◽  
Author(s):  
Yachong Guo ◽  
Emmanuel Terazzi ◽  
Ralf Seemann ◽  
Jean Baptiste Fleury ◽  
Vladimir A. Baulin
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Direct Proof ◽  
Phospholipid Bilayer ◽  
In Situ Observation ◽  
Threshold Size ◽  
Translocation Event ◽  
Electrophysiological Measurements ◽  
Translocation Mechanism ◽  
Optical Fluorescence

Hydrophobic nanoparticles introduced into living systems may lead to increased toxicity, can activate immune cells, or can be used as nanocarriers for drug or gene delivery. It is generally accepted that small hydrophobic nanoparticles are blocked by lipid bilayers and accumulate in the bilayer core, whereas big nanoparticles can only penetrate cells through slow energy-dependent processes, such as endocytosis, lasting minutes. In contrast to expectations, we demonstrate that lipid-covered hydrophobic nanoparticles may translocate through lipid membranes by direct penetration within milliseconds. We identified the threshold size for translocation: nanoparticles with diameters smaller than 5 nm stay trapped in the bilayer, whereas those with diameters larger than 5 nm insert into the bilayer, opening pores in the bilayer. The direct proof of this size-dependent translocation was provided by an in situ observation of a single event of a nanoparticle quitting the bilayer. This was achieved with a specially designed microfluidic device combining optical fluorescence microscopy with simultaneous electrophysiological measurements. A quantitative analysis of the kinetic pathway of a single nanoparticle translocation event demonstrated that the translocation is irreversible and that the nanoparticle can translocate only once. This newly discovered one-way translocation mechanism provides numerous opportunities for biotechnological applications, ranging from targeted biomaterial elimination and/or delivery to precise and controlled trapping of nanoparticles.

scholarly journals Visualization of diffusion limited antimicrobial peptide attack on supported lipid membranes

Soft Matter ◽  
2018 ◽  
Vol 14 (29) ◽  
pp. 6146-6154 ◽  
Author(s):  
George R. Heath ◽  
Patrick L. Harrison ◽  
Peter N. Strong ◽  
Stephen D. Evans ◽  
Keith Miller
Keyword(s):  
Antimicrobial Peptide ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Mechanisms Of Action ◽  
Membrane Disruption ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Rapid Removal ◽  
Supported Lipid Membranes ◽  
Insight Into

Using fast-scanning AFM to capture an antimicrobial peptide attack on planar lipid bilayers allows us to watch membrane disruption in real time. We observed the rapid removal of membrane in a 2D diffusion limited aggregation process giving new insight into antimicrobial peptide mechanisms of action.

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