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. 2004 Nov 19;88(2):1018–1029. doi: 10.1529/biophysj.104.052043

FIGURE 6.

FIGURE 6

Effect of TEA on burst duration. (A) Kinetic scheme for open channel block. Blocker binds only to the open state of the channel. (B) Single-channel records of KcsA in 200 mM symmetric K+ at +200 mV under control conditions and in the presence of 25 mM TEA. Data were sampled at 50 kHz and filtered at 5 kHz. (C) Open dwell-time histograms of single-channel activity recorded under control conditions and in the presence of 25 mM TEA. Single exponential fits to the data yield mean open times of 1.2 and 0.8 ms for control and TEA-blocked channels, respectively. Current is reduced by half at this voltage, indicating that the KD value for rapid block is 25 mM. The open channel block scheme shown in A thus predicts a burst duration of 2.4 ms in the presence of TEA (position shown by arrow).