TABLE 1.
Charge movements expressed by domain chimeras and heptad repeat mutants in β1 KO myotubes
|
Q-V
|
|||
|---|---|---|---|
| Qmax (fC/pF) | V1/2 (mV) | k (mV) | |
| WT β1a | 4.2 ± 0.7* (4) | 24.7 ± 5.2 | 20.1 ± 1.9 |
| WT β2a | 3.5 ± 0.6* (8) | 15.4 ± 7.8 | 19.0 ± 1.7 |
| β2a(D1–D3)/β1a(D4, D5) | 4.0 ± 0.7* (4) | 26 ± 6 | 16.6 ± 2.5 |
| β1a(D1–D3)/β2a(D4, D5) | 4.5 ± 0.4* (5) | 30 ± 2 | 19.7 ± 0.4 |
| β2a(D1–D4)/β1aD5 | 3.5 ± 0.1* (5) | 10 ± 11 | 16.8 ± 3.5 |
| β1a(D1–D4)/β2aD5 | 4.0 ± 0.1* (4) | 11 ± 6 | 17.9 ± 1.9 |
| D5ALA (L478A, V485A, V492A) | 3.8 ± 0.7* (4) | 15 ± 3 | 18.1 ± 2.5 |
| D5ALAc (S481A, L488A, S495A) | 3.9 ± 0.6* (4) | 13 ± 8 | 17.3 ± 2.6 |
| Nontransfected β1 KO | 1.8 ± 0.16† (5) | 16 ± 5 | 11.6 ± 3.1 |
Mean ± SEM of Boltzmann parameters fitted to each cell with number of cells in parenthesis. Qmax, V1/2, and k are parameters of the Boltzmann fit to each cell with Eq. 1.
*
Parameters in each column compared to nontransfected cells with one-way ANOVA significance p < 0.05.
†
Parameters in each column compared to WT β1a with one-way ANOVA significance p < 0.05. Data for WT β1a and WT β2a are from Ahern et al. (2003).