TABLE 3.
Gating parameters of concatenated KCNQ1 and L353K mutant expressed without and with KCNE1
V50 (half-activation voltage) and z (equivalent gating charge) were derived by fitting with a single Boltzmann function and are expressed as mean ± S.E. ΔG0, ΔΔG0, and their standard errors were calculated as described under “Experimental Procedures.” –, not detectable.
| Subunits mutated | Mutation |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| L353K |
L353K + KCNE1 |
|||||||||
| V50 | z | ΔG0 | ΔΔG0 | n | V50 | z | ΔG0 | ΔΔG0 | n | |
| mV | cal/mol | kcal/mol | mV | kcal/mol | kcal/mol | |||||
| WT | −26.6 ± 0.8 | 2.7 ± 0.2 | −1.67 ± 0.01 | 9 | 25.0 ± 0.6 | 1.8 ± 0.1 | 1.01 ± 0.00 | 14 | ||
| D1 | −44.5 ± 1.9 | 2.4 ± 0.4 | −2.51 ± 0.03 | −0.84 ± 0.03 | 6 | 15.5 ± 1.2 | 1.9 ± 0.1 | 0.67 ± 0.00 | −0.35 ± 0.01 | 9 |
| D1,2 | −48.7 ± 2.0 | 3.2 ± 0.8 | −3.54 ± 0.06 | −1.86 ± 0.06 | 8 | 6.6 ± 0.6 | 2.1 ± 0.1 | 0.32 ± 0.00 | −0.70 ± 0.00 | 9 |
| D1,2,3 | −53.5 ± 2.0 | 4.6 ± 1.8 | −5.72 ± 0.15 | −4.05 ± 0.15 | 9 | 6.8 ± 0.5 | 2.1 ± 0.1 | 0.33 ± 0.00 | −0.68 ± 0.00 | 11 |
| D1,2,3,4 | – | – | – | – | 7 | 10.3 ± 0.7 | 2.1 ± 0.1 | 0.50 ± 0.00 | −0.52 ± 0.00 | 8 |