Other tests of factors influencing paxilline block. (A) Paxilline blocks construct Slo1-G310C. Traces show reduction of Slo1-G310C currents by the indicated paxilline concentrations with 10 µM of cytosolic Ca²⁺ and steps to +200 mV. (B) G-V curves are shown for paxilline block of Slo1-G310C. Red line corresponds to fit of voltage-independent block of open and closed states with K_b = 34.6 ± 1.8 nM. (C) Paxilline blocks DN5. Traces show paxilline block of DN5 in which the Slo1 cytosolic structure is replaced by Slo3. Currents were activated with cytosolic pH 8.5 with steps to +280 mV. (D) G-V curves are shown for paxilline block of DN5. Red lines show a fit with K_b = 6.3 ± 0.3 nM with z = 0 e. (E) Paxilline block on MC10-S300G G-V curves is similar at either pH 7.0 (black) or pH 8.5 (red). In both cases, 20 nM paxilline produces similar block. (F) Points plot the peak current during the application of 100 nM paxilline applied to outside-out patches expressing either Slo1 (black) or Slo1-G311S (red). Currents were activated by steps to +200 mV with 10 µM of pipette Ca²⁺ with a holding potential of 0 mV.