Figure 8. Greatly reduced Zn²⁺ sensitivity of the WT–H140A/H193A tandem dimer, compared with the WT–WT tandem dimer.

All current families in the WT–WT tandem dimer (A) or the WT–H140A/H193A tandem dimer (B) were recorded during pulses to the voltages shown in the inset at pH_o 7.0, pH_i 6.5. C and D, the g_H–V relationships were determined from the cells in A and B using reversal potentials measured in each cell.