Figure 2. Voltage dependence of the relative open probability (Po) for WT and Q552R hClC-1 channels.
Currents were recorded from cells using an internal (pipette) solution containing a chloride concentration ([Cl−]) of 134 mm (i.e. standard internal solution). Values for relative Po were derived from normalised peak tail currents at −105 mV and plotted versus the test potential. Data from WT channels (▵, n = 11) can be fitted to a single Boltzmann distribution (continuous line). Data from Q552R channels (□, n = 15) produced an inverted bell-shaped curve with a relative Po higher than that of WT at a resting membrane potential of −85 mV.