Figure 1. Inhibition of TRPM8 currents by scPPX1 in whole-cell patch clamp. Upper panels: Whole-cell patch clamp measurements of menthol-induced currents were performed at −60 mV in the whole-cell configuration on HEK cells expressing TRPM8, in nominally Ca2+-free solution (NCF), to avoid desensitization. Menthol pulses (500 μM) were applied in the first 3–5 min after establishment of whole-cell configuration: HEK-293 cells were transiently transfected with TRPM8 (0.4 μg) and co-transfected with GFP clone (0.2 μg) to allow detection of transfected cells. Panel A: the control. Panel B: the pipette solution was supplemented with 2.3 μg/ml scPPX1. Midle panels: Whole-cell patch clamp was performed on HEK-293 TRPM8 stable cell line, which was transiently transfected with GFP (0.2 μg) alone (panel D) or with scPPX1 clone (0.4 μg) and GFP (0.2 μg) (panel E). The summaries are shown in panel F. The protocol of experiment is the same as for the measurements in the upper panel. Lower panels: Current/Voltage relationships of TRPM8 channels obtained in whole-cell patch clamp performed at −100 +100 mV voltage ramps for HEK-293 TRPM8 stable cell line, which was transiently transfected with GFP (0.2 μg) alone (panel G) or with scPPX1 clone (0.4 μg) and GFP (0.2 μg) (panel H). The summaries are shown in panel I at −100 and +100 mV.