We found that higher concentrations of scPPX1 were toxic for the cells. In control experiments the menthol-activated
TRPM8 currents were found to be 1.8}0.21 and 1.77}0.25 nA (n = 8) for the first and the second pulses of menthol application, while the values were found to be 0.83}0.18 and 0.68}0.16 nA (n = 5) in scPPX1 dialyzed cells. The recordings
were obtained at holding potential of −60 mV. The results are summarized in figure 1C. All the errors are expressed as SEM.