... thesidechains of Glu332 of each rat Kv1.2 a-subunit(Kv1.2 channel is composed of four a-subunits) and Arg10, Arg19, Lys30 and Lys33 of Pi4. The Lys26 sidechain of Pi4 enters into the ion channel pore and ... atoms of the P-domainselectivity filter. Residue Tyr35 of Pi4 is involved in ahydrophobic cluster of aromatic residues consisting of Trp344, from one of the four Kv1.2 a-subunits, and Trp345 and ... &Fig. 8. Functional map of Pi4 towards rat Kv1.2 channel, and comparison with that of Pi1. Functional maps of Pi4 [1] and Pi1 [5–7] (A and B,respectively). The structures of scorpion toxins are...