TABLE I.
Single-Channel Properties and PIP2-apparent Affinities of Kv7.3/7.4 Chimeras at 0 mV
| Cell-attached | Inside-out + 25 μM diC8-PIP2 | ||||
|---|---|---|---|---|---|
| Unitary current (pA) | Po | n | EC50 (μM) | nH | |
| Kv7.3 wt | 0.84 ± 0.09 | 0.78 ± 0.06 | 5 | 6 ± 1 | 2.2 ± 0.4 |
| Kv7.4 wt | 0.19 ± 0.04 | 0.03 ± 0.02 | 9 | 154 ± 1 | 2.3 ± 0.5 |
| Kv7.3N/ Kv7.4C-1 | 0.50 ± 0.14 | 0.12 ± 0.03 | 12 | 180 ± 1 | 1.2 ± 0.1 |
| Kv7.4N/ Kv7.3C-1 | 0.23 ± 0.05 | 0.79 ± 0.09 | 9 | 7 ± 1 | 1.2 ± 0.1 |
| Kv7.3N/ Kv7.4C-2 | 0.49 ± 0.09 | 0.06 ± 0.03 | 5 | 94 ± 1 | 2.2 ± 0.2 |
| Kv7.4N/ Kv7.3C-2 | 0.26 ± 0.07 | 0.79 ± 0.06 | 5 | 12 ± 1 | 2.1 ± 0.3 |
| Kv7.3N/ Kv7.4C-3 | 0.82 ± 0.13 | 0.74 ± 0.12 | 5 | 21 ± 1 | 1.2 ± 0.2 |
| Kv7.4N/ Kv7.3C-3 | 0.12 ± 0.02 | 0.015 ± 0.003 | 6 | 660 ± 1 | 1.8 ± 0.2 |
Given on the left are the values of the unitary current and Po of the indicated wt or chimeric channels in cell-attached patches at 0 mV. Given on the right are the results of Boltmann equation fits of dose–response data of single-channel Po at 0 mV vs. [diC8-PIP2] obtained in inside-out patches. EC50 and nH refer to the [diC8-PIP2] that yield half-maximal Po and the Hill equation coefficient, respectively.