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

Abstract

Ion channel proteins play important roles in various cell functions, making them attractive drug targets. Artificial lipid bilayer recording is a technique used to measure the ion transport activities of channel proteins with high sensitivity and accuracy. However, the measurement efficiency is low. In order to improve the efficiency, we developed a method that allows us to form bilayers on a hydrogel bead and record channel currents promptly. We tested our system by measuring the activities of various types of channels, including gramicidin, alamethicin, α-hemolysin, a voltage-dependent anion channel 1 (VDAC1), a voltage- and calcium-activated large conductance potassium channel (BK channel), and a potassium channel from Streptomyces lividans (KcsA channel). We confirmed the ability for enhanced measurement efficiency and measurement system miniaturizion.

Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology

“…Furthermore, membranes formed at the tip of a glass electrode present the additional advantage of reversible membrane formation. Shoji et al, developed a gold-based electrode where lipids sheets were formed on gold-oil and water-oil interfaces and showed a directional dependency on protein gating [ 124 ], while Hirano et al, expanded this technique towards immobilizing proteins on hydrogel beads for prompt constitution of channels [ 125 ]. Challita et al formed membranes at the interface of an aqueous droplet and a polyethylene glycol dimethacrylate (PEGDMA) hydrogel pipette, submerged in an oil dish [ 126 ] and emphasized reliable and repeatable membrane formation.…”