Reconstitution of the voltage-gated K+ channel KAT1 in planar lipid bilayers

The single-channel current has been recorded for the voltage-gated K+ channel from Arabidopsis thaliana, KAT1, reconstituted in the planar bilayer lipid membrane (BLM). Channel-like current was observed between two aqueous phases after the addition of the proteoliposomes into one aqueous phase. In the potential range from 60 to 120 mV, the single-channel current was recorded and the conductance was calculated to 10.0–12.5 pS. The open channel probability increased with an increase of the applied membrane potential. These characteristics of the reconstituted channels are close to those of KAT1 reported by Hoshi et al. and Hedrich et al. with the patch clamp technique. This is the first work in which the isolated ion channel from higher plants was reconstituted in the planar BLM system.