Figure 4.

Cd²⁺ has two high-affinity effects on gating of Q468C channels. Cd²⁺ was applied to the intracellular side of the patch. At 2.6 μM Cd²⁺ (left), channel opening was slowed, and maximal current and tail current were strongly inhibited. At 130 nM Cd²⁺ (right), currents were less inhibited, and an additional strong effect of Cd²⁺ on channel closing is revealed. Effects of Cd²⁺ were rapidly reversible (<10 s).