Figure 4.

(A) Conductance of single PA₆₃, C2IIa, and Ib channels in the absence (top) and presence of 0.135 μM AmPrβCD (middle row) and AMBnTβCD (bottom row) blockers in the cis side of the chamber. Recordings are shown at 10-ms time resolution. AMBnTβCD displays a significantly longer binding lifetime with all channels compared with AmPrβCD, whereas the time between the blockage events, characterizing the on-rate of the binding reaction, seems to be practically unchanged. (B) The PA₆₃ F427A mutant shows much shorter blockages for both AmPrβCD (middle track) and AMBnTβCD (bottom track) blockers. Recordings are shown at 1-ms time resolution. Other conditions for A and B are the same as for Fig. 2.