BK channels (hslo α) purified using SMALP's can form functional BK channels in planar lipid bilayers.
The recordings are made at ±50 mV in the presence of 50 µM free Ca2+. The planar lipid bilayer was formed from 50 : 50 POPS and POPE. The BKα channel/SMALP complex has inserted into the bilayer backwards and C and O represent the closed and open state. (A) BK single channel currents at −50 mV. (B) The Patlak amplitude histogram of the potassium current flowing through the channel. The histogram has been fitted to two Gaussian curves. The open probability is ∼0.15. (C) BK single channel measurements at +50 mV. BK channel openings are extremely brief and do not achieve a full amplitude due to the filtering of the recording. (D) The Patlak running amplitude histogram of the potassium current flowing through the channel.