Channel variant | A_{1} | B_{1} | C_{1} | A_{2} | B_{2} | C_{2} | D |

L689I DI | 0.53 | 0.01677 | 15.01 | 2.81 | 0.1601 | 137.7 | −2.04 |

L689I DII | 0.16 | 0.00003 | 6.07 | 1.04 | 0.0707 | 28.4 | −0.19 |

L689I DIII | 0.74 | 0.00001 | 6.58 | 0.41 | 0.0002 | 12.9 | −0.19 |

L689I DIV | 0.21 | 0.000001 | 4.23 | 0.87 | 0.0075 | 18.0 | −0.11 |

For F-V curves, two Boltzmann functions fit the curve well: In each case, only one Boltzmann described voltage dependence above −100 mV. To derive the steady-state activated probability for modeling purposes, A was set to 1 and D to 0. The values predicted by this normalized function were used to calculate the steady-state occupancy. Channel variant abbreviations as in Table 1.