Figure 5: Crosslinking analyses by oxidation in the cytoplasmic end of S4.

(a) Schematic illustration of the mutation sites of S215, T218 and the GGG mutation. Constructs' designs were summarized in the Supplementary Fig. S9e. (b) Activation kinetics of the Cys-mutant channels were analysed under the control of temperature with the incubation of 5 mM H₂O₂ (extracellular) or 1 mM DTT (in the pipette) for 15 min . The linear regression lines for the data from WT (black), GGG (blue) and ΔC (blue) channels were indicated. (c) Representative current traces of the GGG+T218C mutant channel before (black, left) and after (red, right) the incubation with H₂O₂. (d) Crosslinking western blot analyses with the oxidation for the Cys-mutant channels. Proteins did not migrate as dimers with reduction (not shown).