Toxin | Kv2.1 | Kv2.2 | Kv2.1/9.3 | Kv4.1 | Kv4.2 | Kv4.3 |
---|---|---|---|---|---|---|
ScTx1 | 12.7 | 21.4 | 7.2 | — | 1.2 | — |
HmTx1 | 23% (100 nM) | 19.7% (100 nM) | N.T. | 280 | 39% (300 nM) | 43% (300 nM) |
HmTx2 | 18% (300 nM) | 0% (300 nM) | N.T. | — | — | — |
HaTx1 | 42 | N.T. | N.T. | N.T. | 70% (500 nM)1-b | N.T. |
PaTx1 | 6% (500 nM)1-a | 16% (500 nM)1-a | N.T. | 39% (250 nM) | 5 | 28 |
PaTx2 | 8% (500 nM)1-a | 11% (500 nM)1-a | N.T. | 20% (300 nM) | 34 | 71 |
HpTx1 | N.T. | N.T. | N.T. | N.T. | 100 | — |
HpTx2 | N.T. | N.T. | N.T. | N.T. | 100 | — |
HpTx3 | N.T. | N.T. | N.T. | N.T. | 67 | — |
Activities of spider toxins against different subtypes of Kv2 and Kv4 potassium channels are reported as IC50 (nanomolar)or as percentage of current inhibition at a single dose (nanomolar). Affinity (IC50) measurements obtained in electrophysiological experiments were obtained using a single site relation model (Hill relation, n H = 1). Data are from this study (ScTx1, HmTx1, 2) or from previously published work for hanatoxin 1 (HaTx1; Swartz and MacKinnon, 1995), phrixotoxins (PaTx1, 2; Diochot et al., 1999), and heteropodatoxins (HpTx1, 2, 3; Sanguinetti et al., 1997).