Table II.
Characteristics of the Currents Mediated by mKv1.7 Mutant Channels Expressed in Xenopus Oocytes Determined by TEVC Measurements
| Charge | V1/2 | Slope | RT75 | τInac | ||||
|---|---|---|---|---|---|---|---|---|
| mV | mV | n | ms | n | ms | n | ||
| mKv1.7L | 7.45 | 4.4 ± 1.4 | 15.4 ± 0.5 | 20 | 4.4 ± 0.5 | 12 | 181.8 ± 15.4 | 15 |
| mKv1.7S | 5.12 | −4.3 ± 2.9 | 13.3 ± 0.6 | 15 | 7.5 ± 0.7 | 12 | 643.2 ± 80.1 | 13 |
| H10K | 8.28 | −5.3 ± 1.2b | 15.3 ± 1.0 | 7 | 7.2 ± 1.4a | 9 | 334.9 ± 40.1c | 7 |
| H21K | 8.28 | −10.1 ± 2.3c | 12.2 ± 0.7b | 7 | 11.0 ± 1.3c | 8 | 225.3 ± 9.0 | 8 |
| H10KH21K | 9.11 | −14.5 ± 2.6c | 11.0 ± 1.6b | 5 | 7.6 ± 0.8b | 5 | 230.4 ± 20.3 | 5 |
| H10Q | 7.28 | −5.1 ± 1.8c | 17.1 ± 1.1 | 7 | 3.4 ± 0.2 | 8 | 394.3 ± 65.8c | 7 |
| H21Q | 7.28 | −1.5 ± 1.7a | 17.5 ± 0.7 | 6 | 3.44 ± 0.3 | 6 | 516.6 ± 71.4c | 5 |
| H10QH21Q | 7.12 | −0.2 ± 1.2 | 17.8 ± 0.5 | 5 | 3.24 ± 0.2 | 6 | 632.5 ± 86.9c | 5 |
| M33I | 7.45 | −4.1 ± 1.2b | 17.2 ± 0.6 | 6 | 4.0 ± 0.5 | 8 | 244.2 ± 51.5 | 8 |
| M33G | 7.45 | −3.5 ± 2.1a | 14.9 ± 0.9 | 3 | 4.7 ± 0.8 | 5 | 127.9 ± 19.7 | 9 |
| C37A | 7.48 | −2.2 ± 1.4b | 16.6 ± 0.4 | 7 | 5.3 ± 0.7 | 9 | 232.7 ± 49.1 | 11 |
| C41A | 7.48 | −0.5 ± 1.2 | 17.0 ± 0.5 | 7 | 3.3 ± 0.3 | 7 | 76.0 ± 3.08c | 9 |
| C43A | 7.48 | −0.1 ± 1.4 | 15.4 ± 0.5 | 5 | 4.5 ± 0.4 | 5 | 89.2 ± 4.9b | 6 |
| C44A | 7.48 | −1.0 ± 1.7 | 17.7 ± 0.4 | 7 | 3.0 ± 0.1a | 8 | 65.4 ± 10.8c | 8 |
| Kv1.7S-H342G | 5.12 | −1.8 ± 3.1 | 16.5 ± 1.5 | 4 | 9.8 ± 1.0 | 4 | 737.6 ± 102.1 | 4 |
| Kv1.7S-C12A | 5.12 | −1.5 ± 1.0 | 14.7 ± 1.7 | 2 | 10.7 ± 1.8 | 2 | 1117.0 ± 38.4 | 2 |
Charge was determined at pH 7 for the N-terminal 182 aa or 150 aa in Kv1.7S. RT75 and τInac were determined at 40 mV.
a
P < 0.01, compared to mKv1.7L.
b
P < 0.001, compared to mKv1.7L.
c
P = 0.0001, compared to mKv1.7L.