FIGURE 6.

Acceleration of spermine unbinding by internal ammonium. A–C, sample currents elicited from Kir6.2[N160D] channels, illustrating spermine unbinding at voltages between −80 and −10 mV, alone or in the presence of 100 mm ammonium (NH₄⁺) or tetramethylammonium (TMA⁺). D, normalized currents depicting spermine unbinding at −50 mV, in control or in the presence of NH₄⁺ or TMA⁺, as indicated. E, summarized data illustrating the rate of spermine (SPM) unbinding between −40 mV and −80 mV, in the presence of 100 mm NH₄⁺ or TMA⁺. Error bars indicate S.E.