Figure 1
Dose–response analysis of the effect of AaH-II on Nav1.2 and Nav1.6 in HEK293 cells expressing either one or the other VGNC. (A) Nav1.2 or Nav1.6 currents, elicited by clamping the Vm from − 100 mV to 0 mV for 50 ms, in control solution and after addition of 0.3 nM or 10 nM of AaH-II. Red and blue traces are the Nav1.2 and Nav1.6 currents, respectively, in the presence of the toxin; on the top-left panel the current parameter T50 with 0.3 nM AaH-II is indicated with the red arrow also in the inset of the reported trace. (B) Mean ± SEM of the normalized half inactivation time increase following AaH-II addition at different concentrations for Nav1.2 and for Nav1.6 currents. Values reported in the plot were as follows. For Nav1.2 (red lines and symbols): 0.01 nM—0.004 ± 0.006 (N = 7); 0.03 nM—0.02 ± 0.01 (N = 6); 0.1 nM 0.13 ± 0.04 (N = 4); 0.3 nM 0.49 ± 0,11 (N = 5); 1 nM—0.92 ± 0.09 (N = 9); 3 nM—1 ± 0.28 (N = 4); 10 nM—0.85 ± 0.12 (N = 6). For Nav1.6 (blue lines and symbols): 0.01 nM—0.01 ± 0.005 (N = 7); 0.03 nM—0.007 ± 0.005 (N = 9); 0.1 nM—0.0009 ± 0.006 (N = 2); 0.3 nM—0.34 ± 0.06 (N = 20); 1 nM—0.89 ± 0.11 (N = 16); 3 nM—1 ± 0.13 (N = 20); 10 nM—0.92 ± 0.13 (N = 17). AaH-II does not discriminate between the two VGNC isoforms.
