Table I

Parameters of the Voltage Dependence of Activation

Channelv1/2*zm (e0)*n*
mV
IFMQ3−29.1 ± 2.7 5.1 ± 1.110
1R2Q−30.1 ± 1.65.5 ± 0.6 4
1R2K−26.3 ± 1.7 4.6 ± 0.5 3
1K4Q−10.6 ± 3.5‡ 3.9 ± 0.6‡ 7
1K4R−25.3 ± 2.5‡ 5.1 ± 0.3 7
2R2Q−24.7 ± 1.5‡4.0 ± 0.8‡ 7
2R2K−20.0 ± 1.8‡ 4.2 ± 0.5 4
2K4Q−14.2 ± 3.1‡ 4.4 ± 0.9 5
2K4R−25.3 ± 1.0‡ 4.9 ± 1.3 5
3R2Q−29.4 ± 1.9 5.5 ± 0.4 5
3R2K−29.5 ± 5.25.5 ± 0.5‡ 4
3R4Q−47.2 ± 6.4‡ 5.4 ± 1.6 5
3R4K−19.3 ± 3.3‡ 4.5 ± 0.9 8
4R2Q−25.5 ± 1.7‡4.6 ± 0.4 5
4R2K−25.0 ± 1.7‡5.1 ± 0.4 3
4R4Q−28.7 ± 1.6 6.0 ± 0.8 7
4R4K−21.7 ± 1.5‡ 5.7 ± 0.3 5
1K4Q:2K4Q−12.2 ± 1.4‡2.6 ± 0.2‡ 7
3R4Q:4R4Q−39.4 ± 1.7‡ 4.5 ± 0.9 6
  • * v1/2 and zm are the half-maximal voltage and gating valence of activation as determined by least-squares fits of the data (n = number of separate determinations) to a two-state Boltzmann function as described in materials and methods.  

  •  Values significantly different from IFMQ3, with a probability <0.05 resulting from random variation (based on Student's unpaired t test).