Figure 8.

Engineering sensitivity to the tarantula toxin GxTx-1E into the Shaker Kv channel. (A) Sequence alignment for S3 helices in Kv2.1 (blue) and Shaker (black) Kv channels. Conserved residues are shown in bold lettering. In the Shaker Δ5 construct, five residues (asterisks) were mutated to the corresponding residues in Kv2.1 (L327I, A328F, V330T, V331E, and A332S). (B and C) Normalized G-V relations in the absence (black circles) and presence (red circles) of hanatoxin or GxTx-1E, both applied to the external solution at a concentration of 2 µM. Conductance was measured using tail currents and the external solution contained 50 mM Rb⁺. Error bars indicate SEM (n = 6).