Gating parameters of Nav1.2, Nav1.4, Nav1.5, and Nav1.5 mutants
The voltage dependence of activation and inactivation, and recovery from fast inactivation were measured by the method described in Materials and Methods. Data represent the mean ± S.D.
| Activation | Inactivation | INa Decay (at 0 mV) | Recovery | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| V1/2 | s | n | V1/2 | s | n | Decay time | n | τ | n | |
| mV | mV | ms | ms | |||||||
| Nav1.2 | −19.4 ± 3.4 | 5.6 ± 0.6 | 8 | −54.1 ± 3.4 | 5.1 ± 0.8 | 8 | 1.3 ± 0.3 | 8 | 1.0 ± 0.3 | 7 |
| Nav1.4 | −22.4 ± 2.5 | 6.4 ± 0.7 | 5 | −60.3 ± 5.1 | 6.7 ± 0.7 | 6 | 1.0 ± 0.1 | 5 | 0.8 ± 0.2 | 5 |
| Nav1.5 | −51.3 ± 5.8 | 5.6 ± 0.4 | 5 | −90.3 ± 6.5 | 4.9 ± 0.6 | 8 | 1.8 ± 1.1 | 5 | 5.5 ± 0.7 | 6 |
| Nav1.5 mutants | ||||||||||
| N406A | −34.0 ± 6.9 | 8.1 ± 1.7 | 6 | −89.0 ± 3.7 | 5.0 ± 0.6 | 8 | 0.9 ± 0.2 | 6 | 1.4 ± 0.3 | 8 |
| L1462A | −38.0 ± 2.7 | 6.4 ± 1.0 | 6 | −92.4 ± 2.4 | 4.8 ± 0.7 | 6 | 0.7 ± 0.1 | 6 | 8.9 ± 1.2 | 6 |
| L1462E | −31.8 ± 6.8 | 6.9 ± 0.8 | 4 | −98.2 ± 4.9 | 5.7 ± 0.9 | 5 | 0.8 ± 0.2 | 4 | 11.6 ± 3.4 | 4 |
| L1462F | −44.4 ± 4.9 | 6.0 ± 0.4 | 5 | −101.0 ± 6.9 | 4.5 ± 0.7 | 12 | 0.5 ± 0.2 | 5 | 11.3 ± 4.5 | 7 |
| F1760A | −52.3 ± 5.9 | 5.8 ± 0.7 | 6 | −81.9 ± 6.0 | 4.8 ± 0.3 | 9 | 2.0 ± 1.0 | 6 | 4.4 ± 0.7 | 6 |
Decay time, time to decay from 90% to 10% of the peak current at 0 mV; n, number of cells; s, slope factor; τ, time constant; V1/2, voltage for half-activation or half-inactivation.