FIGURE 4.
Dependence of WT and K210A on [Cl−]ext. A, dependence on [Cl−]ext of the normalized currents for WT (n = 5, filled squares) and K210A (n = 3, open circles) at 100 mV (error bars are smaller than symbols). Normalization was performed with the current at 100 mm. Curves are fits to Equation 2, with K1/2 as the fitted parameter resulting in values of 71 ± 6 and 116 ± 10 mm for WT and K210A, respectively. B, voltage dependence of K1/2. Symbols are the same as panel A. Lines are fit with Equation 4 with K(0) and z as the fitted parameters resulting in values of 1064 ± 27 and 0.67 ± 0.09 mm for WT and 860 ± 15 and 0.50 ± 0.06 mm for K210A, respectively.