Table 1.
Biophysical properties of mCav1.3L and mCav1.3L-HA.
| Parameter | mCav1.3L | mCav1.3L-HA | p | |||||
|---|---|---|---|---|---|---|---|---|
| Mean | ±SD | n | Mean | ±SD | n | |||
| ICa | Imax [pA/pF] | 50.22 | ±36.72 | 36 | 86.94 | ±33.40 | 8 | <0.01 |
| V0.5 [mV] | -4.09 | ±2.47 | 36 | -13.76 | ±2.00 | 8 | <0.0001 | |
| kact [mV] | 8.87 | ±0.66 | 36 | 6.94 | ±0.81 | 8 | <0.0001 | |
| Inactivation [%] | 66.26 | ±11.17 | 30 | 88.16 | ±1.95 | 7 | <0.0001 | |
| τfast [ms] | 14.92 | ±3.65 | 30 | 12.63 | ±1.98 | 7 | 0.0156 | |
| τslow [ms] | 207.23 | ±77.25 | 30 | 117.39 | ±16.27 | 7 | <0.0001 | |
| Afast | 0.23 | ±0.12 | 30 | 0.75 | ±0.02 | 7 | <0.0001 | |
| Aslow | 0.64 | ±0.11 | 30 | 0.15 | ±0.01 | 7 | <0.0001 | |
| Non-inact | 0.13 | ±0.04 | 30 | 0.10 | ±0.01 | 7 | <0.0001 | |
Cav1.3 channels were expressed in tsA-201 cells and activation parameters were obtained from I–V curves fitted as described in methods. V0.5, voltage of half-maximum activation; kact, steepness of activation curve; Inactivation %, percent inactivation 250 ms after time of peak current. Non-linear curve fits to a double-exponential function revealed time constants for fast (τfast) and slow (τslow) inactivation during 300 ms, and the fraction of ICa normalized to Imax with fast (Afast) and slow (Aslow) inactivation and of a non-inactivating component (non-inact). Data were fitted to a double-exponential function. Welch’s t-test was performed for statistical analysis.