Fig. 8.

Gating behavior and Ag⁺ sensitivity of mSlo1Cys6C. A, The G-V curves of mSlo1Cys6C (filled symbols) in a wide range of [Ca²⁺]_in overlap with those of mSlo1 (open symbols) in various [Ca²⁺]_in : 0 μM (■), 1 μM (●), 10 μM (▴), 100 μM (♦), and 300 μM (★). Each set of data is averaged from five patches. Lines are Boltzmann fits. B, the V_h values of mSlo1Cys6C and BK channels are plotted against [Ca²⁺]_in (in log scale). The connecting lines have no physical meaning. C, macroscopic mSlo1Cys6C currents recorded in 100 μM [Ca²⁺]_in before (top) and after (bottom) 240-s perfusion in 520 nM Ag⁺. The voltage protocol was similar to the one used in Fig. 2A. Notice that the time scales are different in these two sets of recordings. D, the macroscopic G-V profiles of mSlo1Cys6C in 100 μM Ca²⁺ before Ag⁺ modification (●), and in 10 μM (☆) and 100 μM [Ca²⁺]_in (○) after Ag⁺ modification. The Boltzmann fitting results were as follows: V_h = 30 mV, z = 1.02 (100 μM Ca²⁺ before Ag⁺ treatment); V_h = 150 mV, z = 0.88 (10 μM Ca²⁺ after Ag⁺ treatment); V_h = 106 mV, z = 0.74 (100 μM Ca²⁺ after Ag⁺ treatment). E, normalized activation (E1, 200 mV) and deactivation (E2, −120 mV) time course of mSlo1Cys6C currents before (gray) and after (black) Ag⁺ modification.