Table 3. Electrophysiological characteristics of WT and 1493delK mutant sodium channels in HEK293 cells.
| WT | 1493delK | |
| INa amplitude (nA): | (n = 16) | (n = 21) |
| At −20 mV | –6.7±1.3 | –1.3±0.3* |
| Activation: | (n = 14) | (n = 16) |
| V1/2 (mV) | –40.7±1.1 | –39.5±1.7 |
| k (mV) | 6.2±0.3 | 7.5±0.4* |
| Steady-state inactivation: | (n = 13) | (n = 14) |
| V1/2 (mV) | –92.5±2.4 | –94.0±2.3 |
| k (mV) | –6.3±0.4 | –7.5±0.3* |
| Recovery from inactivation: | (n = 10) | (n = 10) |
| τ f (ms) | 8.9±1.2 | 3.8±0.4* |
| τ s (ms) | 93.2±24.9 | 82.8±6.4 |
| Development of slow inactivation: | (n = 9) | (n = 11) |
| τ (ms) | 182.3±22.3 | 825.8±197.5* |
| A (ms) | 0.37±0.04 | 0.22±0.4* |
V1/2, voltage of half-maximal (in)activation; k, slope factor of voltage- dependence of (in)activation; A, fraction of channels that enter the slow inactivated state at t = 1 s; τ, time constant for development of slow inactivation; τ f, fast time constant of recovery from inactivation; τ s, slow time constant of recovery from inactivation.
*
p<0.05 vs WT (Student’s t-test).