*2.3. Measurement Protocols*

The measurement protocol consisted of planar lipid bilayer formation (Figure 1A), capacitance measurement (Figure 1B,C) and measurement of the breakdown voltage of the planar lipid bilayer (Figure 1D,E). *C*, *Ubr*, and *tbr* were determined for each planar lipid bilayer. The capacitance *<sup>C</sup>* was normalized to the area of the hole (*<sup>A</sup>* <sup>=</sup> 1.075 <sup>×</sup> <sup>10</sup>−<sup>8</sup> <sup>m</sup><sup>2</sup> ) to calculate the specific capacitance of the planar lipid bilayer *cBLM*. When a voltagecontrolled measurement system was used, *C* was determined by the planar lipid bilayer discharge method (Figure 1B) [4]. For current-controlled experiments, *C* was measured by converting the capacitance to the time period (Figure 1C), which was described in detail by Kalinowski et al. [26].

Transmembrane voltage on planar lipid bilayer was buid-up using a linearly rising signal. In the voltage-controlled experiments, rapid transmembrane voltage build-up was ensured by seven different slopes of the linearly rising voltage *ku*: 4.8 kV/s, 5.5 kV/s, 7.8 kV/s, 11.5 16.7 kV/s, 21.6 kV/s, and 48.1 kV/s [25]. At the time *tbr*, when a sudden increase in transmembrane current was detected, *Ubr* was measured (Figure 1D). In the current-controlled experiments, a slow build-up of the transmembrane voltage was obtained by five different slopes of the linearly rising current *k<sup>i</sup>* : 0.5 µA/s, 1 µA/s, 4 µA/s, 8 µA/s, and 10 µA/s. At the time *tbr* when a sudden drop of the voltage was detected, we determined *Ubr* (Figure 1E). A linearly rising current signal should produce a quadratic shape of the voltage induced on a planar lipid bilayer, but due to the electrical properties of the experimental system setup, the capacitance and resistance of the chamber flattened the voltage curve.
