Electrochemical Analysis of Alamethicin Reconstituted Planar Bilayer Lipid Membranes Supported on Polypyrrole Membranes

2011 ◽  
Author(s):  
Hao Zhang ◽  
Vishnu Baba Sundaresan ◽  
Sergio Salinas ◽  
Robert Northcutt
Keyword(s):  
Energy Conversion ◽  
Conducting Polymer ◽  
Lipid Membranes ◽  
Cell Membranes ◽  
Mechanical Energy ◽  
Hybrid Membrane ◽  
Electrical Impedance Spectroscopy ◽  
Bilayer Lipid Membranes ◽  
Bilayer Lipid

Conducting polymers possess similarity in ion transport function to cell membranes and perform electro-chemo-mechanical energy conversion. In an in vitro setup, protein-reconstituted bilayer lipid membranes (bioderived membranes)perform similar energy conversion and behave like cell membranes. Inspired by the similarity in ionic function between a conducting polymer membrane and cell membrane, this article presents a thin-film laminated membrane in which alamethicin-reconstituted lipid bilayer membrane is supported on a polypyrrole membrane. Owing to the synthetic and bioderived nature of the components of the membrane, we refer to the laminated membrane as a hybrid bioderived membrane. In this article, we describe the fabrication steps and electrochemical characterization of the hybrid membrane. The fabrication steps include electropolymerization of pyrrole and vesicle fusion to result in a hybrid membrane; and the characterization involves electrical impedance spectroscopy, chronoamperometry and cyclic voltammetry. The resistance and capacitance of BLM have the magnitude of 4.6×109Ω-cm2 and 1.6×10−8 F/cm2.The conductance of alamethicin has the magnitude of 6.4×10−8 S/cm2. The change in ionic conductance of the bioderived membrane is due to the electrical field applied across alamethicin, a voltage-gated protein and produces a measurable change in the ionic concentration of the conducting polymer substrate.

Ligand-Receptor Contact Interactions Using Self-Assembled Bilayer Lipid Membranes

1994 ◽  
Vol 360 ◽  
Author(s):  
A. Leitmannova Ottova ◽  
H. Ti Tien
Keyword(s):  
Lipid Membranes ◽  
Cell Biology ◽  
Bilayer Lipid Membranes ◽  
Contact Interactions ◽  
Bilayer Lipid ◽  
Ion Sensing ◽  
Research Areas ◽  
Self Assembled ◽  
Antigen Antibody

AbstractBiological membranes play a crucial role in signal transduction and information processing as well as in energy conversion. This is owing to the fact that most physiological activities involve some kind of lipid bilayer-based receptor-ligand contact interactions. There are many outstanding examples such as ion sensing, antigen-antibody binding, and ligand/voltage--gated channels, to name a few. One approach to study these interactions in vitro is facilitated by employing artificial bilayer lipid membranes (BLMs). We have focused the efforts on ion and/or molecular selectivity and specificity using newly available self-assembled BLMs on solid support (i.e., s-BLMs), whose enhanced stability greatly aids in research areas of membrane biochemistry, biophysics and cell biology as well as in biosensor designs and molecular devices development. In this paper, our current work along with the experiments carried out in close collaboration with others on s-BLMs will be presented.

Polypyrrole Bridge as a Support for Alamethicin-Reconstituted Planar Bilayer Lipid Membranes

2011 ◽  
Author(s):  
Robert Northcutt ◽  
Vishnu-Baba Sundaresan ◽  
Sergio Salinas ◽  
Hao Zhang
Keyword(s):  
Ion Transport ◽  
Conducting Polymer ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Active Material ◽  
Experimental Studies ◽  
Bilayer Lipid Membrane ◽  
Electrical Impedance Spectroscopy ◽  
Bilayer Lipid ◽  
Ionic Components

Conducting polymer actuators and sensors utilize electrochemical reactions and associated ion transport at the polymer-electrolyte interface for their engineering function. Similarly, a bioderived active material utilizes ion transport through a protein and across a bilayer lipid membrane for sensing and actuation functions. Inspired by the similarity in ion transport process in a bilayer lipid membrane (BLM) and conducting polymers, we propose to build an integrated ionic device in which the ion transport through the protein in the bilayer lipid membrane regulates the electrolytic and mechanical properties of the conducting polymer. This article demonstrates the fabrication and characterization of a DPhPC planar BLM reconstituted with alamethicin and supported on a polypyrrole bridge measuring 100 μm × 500 μm and formed across micro-fabricated gold pads. The assembly is supported on silicon dioxide coated wafers and packaged into an electronic-ionic package for electrochemical characterization. The various ionic components in the integrated ionic device are characterized using electrical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA) measurements. The results from our experimental studies demonstrate the procedure to fabricate a rugged electro active polymer supported BLM that will serve as a platform for chemical, bioelectrical sensing and VOC detection.

Conducting polymer polypyrrole supported bilayer lipid membranes

2005 ◽  
Vol 20 (7) ◽  
pp. 1373-1379 ◽  
Author(s):  
Yong Shao ◽  
Yongdong Jin ◽  
Jianlong Wang ◽  
Li Wang ◽  
Feng Zhao ◽  
...  
Keyword(s):  
Conducting Polymer ◽  
Lipid Membranes ◽  
Bilayer Lipid Membranes ◽  
Bilayer Lipid ◽  
Supported Bilayer

scholarly journals Porous Materials to Support Bilayer Lipid Membranes for Ion Channel Biosensors

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Thai Phung ◽  
Yanli Zhang ◽  
James Dunlop ◽  
Julie E. Dalziel
Keyword(s):  
Ion Channel ◽  
Lipid Membranes ◽  
Electrical Impedance Spectroscopy ◽  
Bilayer Lipid Membranes ◽  
Channel Activity ◽  
Supported Bilayers ◽  
Bilayer Lipid ◽  
Filter Materials ◽  
Hydrophobic Materials ◽  
Sodium Channel Activation

To identify materials suitable as membrane supports for ion channel biosensors, six filter materials of varying hydrophobicity, tortuosity, and thickness were examined for their ability to support bilayer lipid membranes as determined by electrical impedance spectroscopy. Bilayers supported by hydrophobic materials (PTFE, polycarbonate, nylon, and silanised silver) had optimal resistance (14–19 GΩ) and capacitance (0.8–1.6 μF) values whereas those with low hydrophobicity did not form BLMs (PVDF) or were short-lived (unsilanised silver). The ability of ion channels to function in BLMs was assessed using a method recently reported to improve the efficiency of proteoliposome incorporation into PTFE-supported bilayers. Voltage-gated sodium channel activation by veratridine and inhibition by saxitoxin showed activity for PTFE, nylon, and silanised silver, but not polycarbonate. Bilayers on thicker, more tortuous, and hydrophobic materials produced higher current levels. Bilayers that self-assembled on PTFE filters were the longest lived and produced the most channel activity using this method.

Stabilization of bilayer lipid membranes on solid supports by trehalose

1996 ◽  
Vol 39 (2) ◽  
pp. 299-302 ◽  
Author(s):  
T. Hianik ◽  
J. Dlugopolsky ◽  
M. Gyeppessova ◽  
B. Sivak ◽  
H.T. Tien ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Bilayer Lipid Membranes ◽  
Solid Supports ◽  
Bilayer Lipid

scholarly journals Liposomes Prevent In Vitro Hemolysis Induced by Streptolysin O and Lysenin

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 364
Author(s):  
Marcelo Ayllon ◽  
Gamid Abatchev ◽  
Andrew Bogard ◽  
Rosey Whiting ◽  
Sarah E. Hobdey ◽  
...  
Keyword(s):  
Blood Cell ◽  
Lipid Membranes ◽  
Bilayer Lipid Membranes ◽  
Prior Work ◽  
Cellular Targets ◽  
Toxin Binding ◽  
Streptolysin O ◽  
Biological Attack ◽  
Toxin Removal

The need for alternatives to antibiotics in the fight against infectious diseases has inspired scientists to focus on antivirulence factors instead of the microorganisms themselves. In this respect, prior work indicates that tiny, enclosed bilayer lipid membranes (liposomes) have the potential to compete with cellular targets for toxin binding, hence preventing their biological attack and aiding with their clearance. The effectiveness of liposomes as decoy targets depends on their availability in the host and how rapidly they are cleared from the circulation. Although liposome PEGylation may improve their circulation time, little is known about how such a modification influences their interactions with antivirulence factors. To fill this gap in knowledge, we investigated regular and long-circulating liposomes for their ability to prevent in vitro red blood cell hemolysis induced by two potent lytic toxins, lysenin and streptolysin O. Our explorations indicate that both regular and long-circulating liposomes are capable of similarly preventing lysis induced by streptolysin O. In contrast, PEGylation reduced the effectiveness against lysenin-induced hemolysis and altered binding dynamics. These results suggest that toxin removal by long-circulating liposomes is feasible, yet dependent on the particular virulence factor under scrutiny.

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