Parameters of KCNQ1 inhibition by external K+ determined via fitting the Hill equation to the data (see Materials and methods)
| Channel . | IC50 (mM) . | Imax . | nH . | n . |
|---|---|---|---|---|
| Q1 WT | 7.67 ± 1.61 | 0.55 ± 0.02 | 1.02 ± 0.19 | 8 |
| Q1+E1 | 11.42 ± 4.27 | 0.24 ± 0.04*** | 0.87 ± 0.14 | 9 |
| EQQ | 13.40 ± 4.72 | 0.44 ± 0.03** | 0.91 ± 0.23 | 6 |
| Q1+E2 | 16.15 ± 7.62 | 0.13 ± 0.07*** | 0.88 ± 0.17 | 5 |
| Q1+E3 | 17.7 ± 6.26* | 0.54 ± 0.05 | 0.93 ± 0.09 | 8 |
| E261A | 3.47 ± 1.48* | 0.35 ± 0.04** | 0.77 ± 0.26 | 4 |
| L271A | 7.01 ± 0.57 | 0.53 ± 0.02 | 1.17 ± 0.19 | 4 |
| I274A | 7.24 ± 1.31 | 0.41 ± 0.03** | 1.41 ± 0.39 | 9 |
| F279A | 10.3 ± 2.31 | 0.47 ± 0.02 | 0.96 ± 0.14 | 5 |
| E290A | 7.01 ± 1.81 | 0.36 ± 0.04** | 1.13 ± 0.18 | 6 |
| E290P | 6.71 ± 1.17 | 0.51 ± 0.04 | 1.07 ± 0.24 | 5 |
| E290R | 5.98 ± 0.79 | 0.61 ± 0.03** | 1.04 ± 0.15 | 5 |
| E290Q | 4.03 ± 1.12* | 0.62 ± 0.04** | 1.02 ± 0.31 | 4 |
| S291A | 9.14 ± 3.98 | 0.63 ± 0.05* | 0.89 ± 0.39 | 6 |
| E295A | 15.12 ± 5.91 | 0.71 ± 0.04** | 0.92 ± 0.16 | 9 |
| F335A | 1.19 ± 0.20* | 0.17 ± 0.04*** | 0.91 ± 0.33 | 4 |
| F351A | 5.64 ± 0.73 | 0.58 ± 0.02 | 1.10 ± 0.13 | 10 |
| F351A Rb+ | 1.81 ± 0.17***# | 0.71 ± 0.02***# | 1.16 ± 0.09 | 8 |
| V355A | 3.12 ± 1.89 | 0.44 ± 0.07 | 0.87 ± 0.28 | 4 |
| Channel . | IC50 (mM) . | Imax . | nH . | n . |
|---|---|---|---|---|
| Q1 WT | 7.67 ± 1.61 | 0.55 ± 0.02 | 1.02 ± 0.19 | 8 |
| Q1+E1 | 11.42 ± 4.27 | 0.24 ± 0.04*** | 0.87 ± 0.14 | 9 |
| EQQ | 13.40 ± 4.72 | 0.44 ± 0.03** | 0.91 ± 0.23 | 6 |
| Q1+E2 | 16.15 ± 7.62 | 0.13 ± 0.07*** | 0.88 ± 0.17 | 5 |
| Q1+E3 | 17.7 ± 6.26* | 0.54 ± 0.05 | 0.93 ± 0.09 | 8 |
| E261A | 3.47 ± 1.48* | 0.35 ± 0.04** | 0.77 ± 0.26 | 4 |
| L271A | 7.01 ± 0.57 | 0.53 ± 0.02 | 1.17 ± 0.19 | 4 |
| I274A | 7.24 ± 1.31 | 0.41 ± 0.03** | 1.41 ± 0.39 | 9 |
| F279A | 10.3 ± 2.31 | 0.47 ± 0.02 | 0.96 ± 0.14 | 5 |
| E290A | 7.01 ± 1.81 | 0.36 ± 0.04** | 1.13 ± 0.18 | 6 |
| E290P | 6.71 ± 1.17 | 0.51 ± 0.04 | 1.07 ± 0.24 | 5 |
| E290R | 5.98 ± 0.79 | 0.61 ± 0.03** | 1.04 ± 0.15 | 5 |
| E290Q | 4.03 ± 1.12* | 0.62 ± 0.04** | 1.02 ± 0.31 | 4 |
| S291A | 9.14 ± 3.98 | 0.63 ± 0.05* | 0.89 ± 0.39 | 6 |
| E295A | 15.12 ± 5.91 | 0.71 ± 0.04** | 0.92 ± 0.16 | 9 |
| F335A | 1.19 ± 0.20* | 0.17 ± 0.04*** | 0.91 ± 0.33 | 4 |
| F351A | 5.64 ± 0.73 | 0.58 ± 0.02 | 1.10 ± 0.13 | 10 |
| F351A Rb+ | 1.81 ± 0.17***# | 0.71 ± 0.02***# | 1.16 ± 0.09 | 8 |
| V355A | 3.12 ± 1.89 | 0.44 ± 0.07 | 0.87 ± 0.28 | 4 |
IC50, concentration of half-maximal inhibition; Imax, the maximal inhibition; nH, the Hill coefficient. Data are represented as mean ± SEM. One-way ANOVA, Dunnett’s post-hoc test, *P < 0.05, **P < 0.01, ***P < 0.001; #, Student’s t test; comparison group is F351A for K+o conditions.