All the following bilayer experiments were conducted in presence of 1% 1,2-dipalmitoyl (diC16) PtdIns(4,5)P2, which resulted in higher stability of the planar lipid bilayers in comparison to the short chain diC8 PtdIns(4,5)P2. No
menthol-activated channels were observed in presence of PtdIns(4,5)P2 on plasma membrane fractions from HEK-293 cells not expressing TRPM8, total 11 experiments were conducted from three different plasma membrane preparations
(data not shown). After the conditions for obtaining the channels in lipid bilayers were established, we found that TRPM8 demonstrated different open probability and gating modes for current flowing in outward and inward directions. A single-channelcurrent-voltage relationship, and open probabilities are presented in Fig. 6 (A–C).