Figure 3.
Linker between S5 and S6 forms the pore region of MaxiK channels. (A) IbTx sensitivity of Hslo. IbTx (100 nM) applied to the external side of an outside-out patch, completely blocks ionic currents. Holding potential = 0 mV; test potential = 80 mV. (Right): Time course of IbTx blockade at different IbTx concentrations. (Insert) Dose-response curve, Kd = 0.72 nM, Hill coefficient near one. (B) Dslo currents are insensitive to 100 nM IbTx. (C) Chimeric construct HDP carries the pore of Dslo in the Hslo backbone. Current traces show that the pore of Dslo makes Hslo insensitive to 100 nM IbTx.