A Simple Method for Ion Channel Recordings Using Fine Gold Electrode

Abstract

The artificial bilayer single-channel recording technique is commonly used to observe detailed pharmacological properties of various ion channel proteins. It permits easy control of the solution and membrane lipid composition, and is also compatible with pharmacological screening devices. However, its use is limited due to low measurement efficiency. Here, we develop a novel artificial bilayer single-channel recording technique in which bilayers are made and channels are reconstituted into the membranes by contacting a gold electrode to the lipid-solution interface. Using this technique, we measured the single-channel currents of two channel-forming peptides, gramicidin and alamethicin, and a channelforming protein, α-hemolysin. This technique requires only one action, allowing the technique to potentially be combined with high-throughput screening devices.

Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology

“…The preference of this approach over previously discussed solid supported membranes is enhanced when interested in single-channel recordings [ 121 , 122 ]. The first attempt of these membranes led to 5–20 GΩ membranes while following efforts reached up to 100 GΩ by using a polyethylene glycol (PEG)–coated gold electrode [ 123 ]. In a comparison between membranes formed by the tip-dip method and membranes formed by the painting technique in studying gramicidin, Matsuno et al found that even though both techniques enable reliable channel recordings, the tip-dip approach formed more stable and long lasting membranes allowing for minutes long recordings otherwise unachieved [ 121 ].…”

De-Insertion Current Analysis of Pore-Forming Peptides and Proteins Using Gold Electrode-Supported Lipid Bilayer

“…We define this analytical method as de-insertion current analysis (DiCA). To enable the measurement of the de-insertion currents, we have employed a gold needle-supported lipid bilayer that is formed by inserting the needle into a layered solution of an aqueous solution and an oil/lipid mixture [4][5][6]. Because the bilayer can be unzipped by pulling up the needle, the de-insertion currents are obtained by recording the current when pulling up the needle (Fig.…”

A Lipid Bilayer Formed on a Hydrogel Bead for Single Ion Channel Recordings

“…By contacting the lipid monolayer at the surface of the probe with another lipid monolayer formed at the interface between the lipid solution and aqueous recording solution, a lipid bilayer membrane was formed at the same time as the channels were incorporated into the membrane. Since lipid bilayer membranes containing ion channels were formed in a single step, channel currents could be measured with high efficiency [19][20][21].…”