FIGURE 11.

Blocker- and position-dependent effects of modification on blocker potency. A–D, for positions 169C and 212C; extremely slow (60 s) voltage ramps between −80 mV and +60 mV were used to assess the voltage dependence of block for various blockers (100 μm). E, ΔV_½ was determined as the difference in V_½ of block for modified versus unmodified channels (n = 3–7 per condition). V_½ values of block were derived from either voltage step protocols (e.g. Fig. 2) or slow voltage ramps, as depicted in panels A–D. Error bars indicate S.E.