Influence of HpTx2 on V1/2 and k values of steady-state channel properties
All values are given in millivolts as mean ± S.E.M., n = 4 to 6. The [HpTx2] was 2 μM except for Kv4.1[(L275,F276)A] with which 5 μM HpTx2 was used. Kv4.3 conductance values are from DeSimone et al. (2009).
| Channel | Conductance | Steady-State Inactivation | ||||||
|---|---|---|---|---|---|---|---|---|
| Control | +HpTx2 | Control | +HpTx2 | |||||
| V1/2 | k | V1/2 | k | V1/2 | k | V1/2 | k | |
| Kv4.1 | −1.8 ± 0.7 | 16.4 ± 0.4 | 8.4 ± 1.0 | 17.17 ± 0.3 | −49.5 ± 0.06 | 6.0 ± 0.06 | −47.2 ± 0.02 | 6.7 ± 0.02 |
| Kv4.3 | 6.1 ± 0.7 | 16.1 ± 0.2 | 28.1 ± 1.4 | 13.6 ± 0.6 | −39.1 ± 1.0 | 4.9 ± 0.02 | −20.7 ± 1.8 | 8.8 ± 0.1 |
| Kv4.1 [(L275,F276)A] | 4.4 ± 0.7 | 14.0 ± 0.6 | 6.1 ± 1.0 | 13.8 ± 0.7 | −48.2 ± 0.3 | 6.0 ± 0.02 | −48.7 ± 0.3 | 6.7 ± 0.02 |
| Kv4.1 [276VMTN] | 0.1 ± 1.0 | 16.8 ± 0.1 | 32.2 ± 2.2 | 16.8 ± 1.7 | −49.2 ± 0.02 | 5.0 ± 0.02 | −33.2 ± 0.01 | 9.3 ± 0.01 |
| Kv4.3 [276FVPK] | 6.8 ± 0.5 | 15.0 ± 0.1 | 16.5 ± 0.5 | 15.0 ± 0.5 | −35.0 ± 0.04 | 5.6 ± 0.03 | −31.5 ± 0.08 | 5.9 ± 0.07 |
| KV4.1 model | −1.5 | 19.6 | 14.8 | 22.6 | N.A. | N.A. | N.A. | N.A. |
| KV4.3 model | 9.6 | 16.0 | 34.5 | 15.6 | N.A. | N.A. | N.A. | N.A. |
N.A., not applicable.