Figure 3.
Effect of charge-neutralizing mutations on suramin block. A, example macroscopic current–voltage relationships for different channel variants in inside-out patches. In each case currents were recorded before (control, black) and after (red) addition of 10 μm suramin to the intracellular solution. B, mean fraction of control current remaining following addition of this concentration of suramin as a function of voltage in these channel variants. C, mean Kd (at −100 mV) calculated from data such as that shown in B as described under “Experimental Procedures” (Equation 1). Asterisks indicate a significant difference from wildtype. *, p < 0.05; **, p < 0.0005. The means of data from 4–10 patches are shown in B and C.