Fig. 1.

Molecular models of αHL and βCD. (A) Sagittal section through a model of WT αHL built by using the coordinates from the crystal structure of the pore (6). The mutated side chains, Met (M)-113, Glu (E)-111, and Lys (K)-147, which lie in the channel lumen, are shown. (B) Structure of βCD. (C) Model of the WT αHL pore showing a model of βCD docked in the lumen of the channel. The location shown is for βCD presented from the trans side of the bilayer and is based on mutagenesis data (1, 2, 5). In our apparatus, in a positive applied potential, the trans side of the membrane is positive relative to the cis side, which is taken as ground.