Effects of mutations in S2 and S4 on voltage-dependent gating of hERG
| Construct | 537/538a | V1/2b | kb | ΔG0c | ΔΔG0d,e | n | Stabilized statef | ΔΔG0,NAg |
| mV | mV | kJ mol−1 | kJ mol−1 | kJ mol−1 | ||||
| WT (2 s) | RK | −27.7 ± 1.1 | 8.2 ± 0.1 | −8.4 ± 0.4 | NA | 13 | NA | NA |
| WT (10 s) | RK | −33.9 ± 1.2 | 7.5 ± 0.2 | −10.5 ± 1.0 | NA | 13 | NA | NA |
| WT (15 s) | RK | −35.1 ± 1.2 | 7.3 ± 0.2 | −12.1 ± 0.7 | NA | 13 | NA | NA |
| F463M | RK | −33.6 ± 2.3 | 9.7 ± 0.8 | −8.8 ± 1.2 | −0.4 ± 1.2 | 5 | NA | NA |
| F463W | RK | −7.1 ± 2.8 | 10.6 ± 0.6 | −1.6 ± 0.6 | 10.5 ± 0.9 | 7 | C | NA |
| F463L | RK | −21.3 ± 1.5 | 8.3 ± 0.3 | −6.3 ± 0.5 | 2.1 ± 0.7 | 6 | NA | NA |
| F463Y | RK | 12.2 ± 1.3 | 6.2 ± 0.3 | −4.8 ± 0.3 | 16.9 ± 0.8 | 4 | C | NA |
| F463V | RK | −23.1 ± 2.2 | 10.5 ± 0.9 | −5.9 ± 1.0 | 2.5 ± 1.1 | 8 | NA | NA |
| K525R | RK | −76.5 ± 3.3 | 8.5 ± 0.4 | −22.5 ± 18 | −14.1 ± 1.9 | 8 | O | NA |
| R537K | KK | −10.1 ± 1.3 | 9.7 ± 0.4 | −2.6 ± 0.4 | 5.8 ± 0.6 | 9 | C | NA |
| R537Q | QK | −16.6 ± 0.7 | 9.1 ± 0.3 | −4.5 ± 0.2 | 3.9 ± 0.5 | 7 | NA | NA |
| K538R | RR | 9.2 ± 1.4 | 8.3 ± 0.1 | 2.7 ± 0.4 | 13.2 ± 1.1 | 7 | C | NA |
| R537Q/K538R | QR | −10.2 ± 0.9 | 8.6 ± 0.7 | −3.0 ± 0.4 | 7.4 ± 1.1 | 7 | C | 11.7 ± 1.1 |
| R537K/K538R | KR | −3.1 ± 2.2 | 8.9 ± 0.3 | −0.9 ± 0.6 | 9.5 ± 1.2 | 6 | C | 11.5 ± 1.3 |
| K538Q | RQ | −65.6 ± 1.6 | 6.1 ± 0.1 | −26.5 ± 0.7 | −18.1 ± 0.9 | 5 | O | NA |
| R537K/K538Q | KQ | −49.0 ± 0.8 | 7.1 ± 0.2 | −17.1 ± 0.8 | −8.7 ± 0.9 | 8 | O | 3.6 ± 1.2 |
| R537Q/K538Q | −49.7 ± 1.8 | 6.8 ± 0.2 | −17.7 ± 0.9 | −9.3 ± 1.0 | 6 | O | 4.9 ± 1.3 | |
| D466E | RK | −27.5 ± 2.0 | 10.5 ± 1.3 | −6.8 ± 1.0 | 1.6 ± 1.1 | 5 | NA | NA |
| D466E/K525R | RK | −34.3 ± 1.1 | 13.4 ± 0.3 | −6.3 ± 0.1 | 2.1 ± 0.5 | 6 | NA | 14.7 ± 2.1 |
| D466E/R537K | KK | 9.6 ± 1.2 | 15.7 ± 0.5 | 1.5 ± 0.2 | 9.9 ± 0.5 | 7 | C | 2.6 ± 1.2 |
| D466E/K538R | RR | −12.5 ± 1.1 | 10.2 ± 0.6 | −3.1 ± 0.5 | 7.3 ± 1.1 | 7 | C | 9.5 ± 1.5 |
| K525Q | RK | −116.0 ± 2.2 | 16.1 ± 0.9 | −18.0 ± 0.8 | −9.6 ± 0.9 | 9 | O | NA |
| D466E/K525Q | RK | −47.0 ± 1.5 | 11.6 ± 0.5 | −10.1 ± 0.5 | −1.7 ± 0.9 | 12 | NA | 10.1 ± 1.4 |
| F463W/K525R | RK | 13.7 ± 1.3 | 16.3 ± 1.1 | 2.1 ± 0.1 | 14.1 ± 0.7 | 5 | C | 14.1 ± 2.0 |
| F463W/R537K | KK | 8.3 ± 1.2 | 11.9 ± 0.2 | 1.7 ± 0.2 | 13.8 ± 0.7 | 5 | C | 6.2 ± 1.0 |
| F463W/K538R | RR | 17.0 ± 2.5 | 15.4 ± 0.3 | 2.7 ± 0.4 | 14.8 ± 0.7 | 8 | C | 10.5 ± 1.1 |
| Construct | 537/538a | V1/2b | kb | ΔG0c | ΔΔG0d,e | n | Stabilized statef | ΔΔG0,NAg |
| mV | mV | kJ mol−1 | kJ mol−1 | kJ mol−1 | ||||
| WT (2 s) | RK | −27.7 ± 1.1 | 8.2 ± 0.1 | −8.4 ± 0.4 | NA | 13 | NA | NA |
| WT (10 s) | RK | −33.9 ± 1.2 | 7.5 ± 0.2 | −10.5 ± 1.0 | NA | 13 | NA | NA |
| WT (15 s) | RK | −35.1 ± 1.2 | 7.3 ± 0.2 | −12.1 ± 0.7 | NA | 13 | NA | NA |
| F463M | RK | −33.6 ± 2.3 | 9.7 ± 0.8 | −8.8 ± 1.2 | −0.4 ± 1.2 | 5 | NA | NA |
| F463W | RK | −7.1 ± 2.8 | 10.6 ± 0.6 | −1.6 ± 0.6 | 10.5 ± 0.9 | 7 | C | NA |
| F463L | RK | −21.3 ± 1.5 | 8.3 ± 0.3 | −6.3 ± 0.5 | 2.1 ± 0.7 | 6 | NA | NA |
| F463Y | RK | 12.2 ± 1.3 | 6.2 ± 0.3 | −4.8 ± 0.3 | 16.9 ± 0.8 | 4 | C | NA |
| F463V | RK | −23.1 ± 2.2 | 10.5 ± 0.9 | −5.9 ± 1.0 | 2.5 ± 1.1 | 8 | NA | NA |
| K525R | RK | −76.5 ± 3.3 | 8.5 ± 0.4 | −22.5 ± 18 | −14.1 ± 1.9 | 8 | O | NA |
| R537K | KK | −10.1 ± 1.3 | 9.7 ± 0.4 | −2.6 ± 0.4 | 5.8 ± 0.6 | 9 | C | NA |
| R537Q | QK | −16.6 ± 0.7 | 9.1 ± 0.3 | −4.5 ± 0.2 | 3.9 ± 0.5 | 7 | NA | NA |
| K538R | RR | 9.2 ± 1.4 | 8.3 ± 0.1 | 2.7 ± 0.4 | 13.2 ± 1.1 | 7 | C | NA |
| R537Q/K538R | QR | −10.2 ± 0.9 | 8.6 ± 0.7 | −3.0 ± 0.4 | 7.4 ± 1.1 | 7 | C | 11.7 ± 1.1 |
| R537K/K538R | KR | −3.1 ± 2.2 | 8.9 ± 0.3 | −0.9 ± 0.6 | 9.5 ± 1.2 | 6 | C | 11.5 ± 1.3 |
| K538Q | RQ | −65.6 ± 1.6 | 6.1 ± 0.1 | −26.5 ± 0.7 | −18.1 ± 0.9 | 5 | O | NA |
| R537K/K538Q | KQ | −49.0 ± 0.8 | 7.1 ± 0.2 | −17.1 ± 0.8 | −8.7 ± 0.9 | 8 | O | 3.6 ± 1.2 |
| R537Q/K538Q | −49.7 ± 1.8 | 6.8 ± 0.2 | −17.7 ± 0.9 | −9.3 ± 1.0 | 6 | O | 4.9 ± 1.3 | |
| D466E | RK | −27.5 ± 2.0 | 10.5 ± 1.3 | −6.8 ± 1.0 | 1.6 ± 1.1 | 5 | NA | NA |
| D466E/K525R | RK | −34.3 ± 1.1 | 13.4 ± 0.3 | −6.3 ± 0.1 | 2.1 ± 0.5 | 6 | NA | 14.7 ± 2.1 |
| D466E/R537K | KK | 9.6 ± 1.2 | 15.7 ± 0.5 | 1.5 ± 0.2 | 9.9 ± 0.5 | 7 | C | 2.6 ± 1.2 |
| D466E/K538R | RR | −12.5 ± 1.1 | 10.2 ± 0.6 | −3.1 ± 0.5 | 7.3 ± 1.1 | 7 | C | 9.5 ± 1.5 |
| K525Q | RK | −116.0 ± 2.2 | 16.1 ± 0.9 | −18.0 ± 0.8 | −9.6 ± 0.9 | 9 | O | NA |
| D466E/K525Q | RK | −47.0 ± 1.5 | 11.6 ± 0.5 | −10.1 ± 0.5 | −1.7 ± 0.9 | 12 | NA | 10.1 ± 1.4 |
| F463W/K525R | RK | 13.7 ± 1.3 | 16.3 ± 1.1 | 2.1 ± 0.1 | 14.1 ± 0.7 | 5 | C | 14.1 ± 2.0 |
| F463W/R537K | KK | 8.3 ± 1.2 | 11.9 ± 0.2 | 1.7 ± 0.2 | 13.8 ± 0.7 | 5 | C | 6.2 ± 1.0 |
| F463W/K538R | RR | 17.0 ± 2.5 | 15.4 ± 0.3 | 2.7 ± 0.4 | 14.8 ± 0.7 | 8 | C | 10.5 ± 1.1 |
Superscripted numerals above each parameter refer to the equation used to calculate the parameter (see Materials and methods). Data are shown as means ± SEM. NA, not applicable.
Letters denote the identities of the residues at positions 537 and 538.
Eq. 1 was used to calculate the parameter.
Eq. 2 was used to calculate the parameter.
Eq. 3 was used to calculate the parameter.
Eq. 4 was used to calculate the parameter.
Defined as a ΔΔG0 > |4.2| kJ mol−1.
Eq. 5 was used to calculate the parameter.