Figure 6.
Role of conformational dynamics in the interaction of ShK and HmK with KV1.3. a) Structure and sequence of ShK (teal) and HmK (green). The disulfide bonds are represented as orange sticks and the Lys-Tyr dyad is shown as sticks. b) The 20 structures derived from PC1 and PC2 show that the dynamics of ShK are distributed throughout the peptide, with the helix 21–24 having a higher contribution, while HmK does not display significant dynamics, except at the N- and C-termini. The final frames of the 100 ns MD simulations show the interaction of KV1.3 (subunits A, and C colored pink and purple, respectively) with c) ShK (teal) and d) HmK (green). The residues in the selectivity filter and the outer vestibule of KV1.3 are the main residues interacting with the α-helix 21–24 of ShK, except for Arg11, which is located in the N-terminal region of the toxin. Both models show Lys22 occupying the pore.