Fig. 3. Interaction of nonaarginine with the cis side of the gpPorA. (a) Electrical recordings showing nonaarginine (R9) interaction with single gpPorA (0.5 μM, cis) at −5 mV and −20 mV. (b) Electrical recordings showing R9 interaction with single gpPorA (0.5 μM, cis) at −35 mV and a plot of koffversus the applied voltage (mean values (±s.d.) from three independent experiments are shown). (c) Electrical recordings showing R9 interaction with single gpPorA (0.5 μM, cis) at +10 mV, +35 mV against electrophoretic mobility (mean values (±s.d.) from three independent experiments are shown). Inset, recording at expanded time scale and the corresponding τoff dwell time histogram. Model showing the interaction of R9 with the cis side of the pores. Electrolyte: 0.15 M KCl, 10 mM HEPES, pH 7.4. The current signals (a) were digitally filtered at 1 kHz, (b) −35 mV at 5 kHz and (c) +10 mV and +35 mV at 1 kHz and 5 kHz using an 8-pole Bessel digital filter.
