FIGURE 5.

Cadmium inhibition in constitutively open channels. A, example whole cell currents recorded at +30 mV for T338C/S1118C (left panel) and T338C/S1118C/E1371Q (right panel), showing the increased sensitivity to inhibition by external Cd²⁺ (10 μm) in E1371Q-containing channels. B, effect of the E1371Q mutation on Cd²⁺ sensitivity in single and double cysteine mutants. Cadmium concentrations, chosen to give ∼50% inhibition for each mutant, are given below the name of the mutant used. Asterisks indicate a significant difference from the effect in a Glu-1371 background (p < 0.05). The means of data from three to four cells are shown. Ctrl, control.