Figure 1. Effects on channel gating of alanine substitutions of 20 residues flanking Phe¹⁵¹⁹ in IIIS6 of BgNa_v1-1A.

Voltages of half-maximal activation or steady-state inactivation (V_0.5) of mutant channels were compared with that of the wild-type sodium channel. The histograms show the differences between voltage for the half-maximal activation or inactivation of wild-type and each mutant sodium channel. V_0.5 values were obtained from Boltzmann fits, as described in the Experimental section. Asterisks indicate significant differences from the wild-type channel as determined by Student’s t test (P <0.05).