FIGURE 5.

Single-channel recordings of EcChiP in artificial lipid membranes. Lipid bilayers were formed across a 70 μm aperture by the lowering and raising technique, using 5 mg·ml⁻¹ 1,2-diphytanoyl-sn-glycero-3-phosphatidylcholine in n-pentane and 1 m KCl in 20 mm HEPES, pH 7.5, on both sides of the chamber. The protein was added to the cis side. A, fully open EcChiP current trace at +100 mV. B, multiple channel insertions; Inset, histogram of the conductance steps observed with 1,2-diphytanoyl-sn-glycero-3-phosphatidylcholine artificial bilayer for 365 independent channel insertions. The black line represents a single Gaussian fit. C, stepwise ramping of the potential for single insertion. Inset, I-V plot for a single EcChiP single channel. The average current values were obtained by varying the potential from −100 mV to +100 mV in 25 mV steps for 17 independent channel insertions. D, gating behavior of EcChiP at high potential (+200 mV).