Alterations of the mid-voltage of activation (V0.5) derived from conductance-voltage (G-V) curves of DmNav1 and rNav1.4 induced by depressant toxins and their mutants
The V0.5 values are from the G-V curves presented in Fig. 5. Depressant toxin effect on rNav1.4 exhibit two components: a minor negative shift in the V0.5 of the entire channel population (upper number) and a stronger shift in the V0.5 of a fraction of the toxin-modified channel population (lower number), indicated by the numbers in parentheses. The data represent the mean ± S.E.M. of at least six independent experiments.
Toxin | DmNav1 | DmNav1 V0.5 | rNav1.4 | rNav1.4 V0.5 |
|---|---|---|---|---|
| μM | mV | μM | mV | |
| Control | -19.1 ± 0.5 | -26 ± 0.2 | ||
| Lqh-dprIT3 | 0.2 | -35.4 ± 0.7 | 5 | -31 ± 0.7 |
| -50.7 ± 2.3 (23%) | ||||
| Lqh-dprIT3E24N | 1 | -20.2 ± 06 | 1 | -38.5 ± 0.3 |
| -60.4 ± 1.5 (11%) | ||||
| LqhIT2 | 1 | -33.1 ± 0.4 | 5 | -30 ± 0.2 |
| -52 ± 3.5 (8%) | ||||
| LqhIT2K23A | 5 | -20.8 ± 0.7 | 5 | -27.2 ± 1.5 |
| LqhIT2E24A | 5 | -18.6 ± 0.6 | 5 | -33.5 ± 1.5 |
| -54.5 ± 9 (15%) | ||||
| LqhIT2E24N | 5 | -19 ± -0.5 | 5 | -32.8 ± 1.4 |
|
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|
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| -43.1 ± 4.1 (62%) |