Table 1. Parameters of Boltzmann fits to GV, FV, SSI, and SSI-FV curves
Channel variantGV/FVSSI/SSI-FV
V1/2kPVPkV1/2kPVPk
mVmVmVmV
GV and SSI
WT−35.3 ± 2.58.5 ± 0.5−83.6 ± 1.67.3 ± 0.4
WT-LFS−36.0 ± 2.18.6 ± 0.4−88.5 ± 1.36.4 ± 0.2
DI-LFS−57.7 ± 1.77.5 ± 1.4−78.0 ± 1.46.5 ± 0.2
DII-LFS−36.4 ± 1.78.7 ± 1.1−82.0 ± 1.57.7 ± 1.0
DIII-LFS−39.9 ± 2.29.5 ± 0.4−76.2 ± 1.26.7 ± 0.2
DIV-LFS−33.4 ± 2.59.3 ± 0.4−71.4 ± 1.010.0 ± 0.6
IQM-LFS−30.9 ± 2.09.2 ± 0.20.14280.2269−52.0 ± 2.17.3 ± 1.93.8 × 10−60.1770
A1330P−36.0 ± 1.97.7 ± 0.40.80620.2825−74.6 ± 1.16.6 ± 0.50.00170.2597
N1325S−42.5 ± 0.32.6 ± 0.70.06893.2 × 10−4−68.3 ± 3.75.4 ± 0.20.00450.0102
N1659A−23.7 ± 2.49.7 ± 0.30.00850.1639−52.6 ± 1.57.5 ± 1.01.6 × 10−70.7790
DI-IQM−48.7 ± 4.511.4 ± 0.50.09210.0528−66.2 ± 2.03.7 ± 1.00.00230.0136
DII-IQM−32.4 ± 0.89.3 ± 0.30.05460.6054−49.3 ± 0.84.1 ± 0.54.4 × 10−70.0547
DIII-IQM−41.0 ± 2.310.8 ± 0.90.95020.0537−59.0 ± 1.24.0 ± 0.61.5 × 10−51.9 × 10−4
DIV-IQM−39.3 ± 2.611.1 ± 1.00.13670.0413−58.8 ± 2.63.4 ± 0.70.01834.8 × 10−4
DIII-N1325S−52.1 ± 1.010.2 ± 1.60.00590.2699−79.9 ± 3.67.7 ± 0.70.27550.1921
DIII-A1330P−51.1 ± 2.79.8 ± 0.60.00810.9331−79.4 ± 3.911.6 ± 0.60.36191.4 × 10−7
DIII-N1659A−37.6 ± 5.910.8 ± 0.50.59770.9349−42.5 ± 1.45.0 ± 0.51.1 × 10−102.3 × 10−5
DIV-N1659A−4.9 ± 1.111.4 ± 0.29.5 × 10−84.6 × 10−5−48.6 ± 4.07.0 ± 0.50.00469.5 × 10−4
FV and SSI-FV
DI-LFS−100.4 ± 4.118.6 ± 1.0−83.4 ± 2.615.6 ± 1.3
DII-LFS−48.6 ± 3.320.9 ± 1.6−48.8 ± 3.518.0 ± 0.9
DIII-LFS−106.1 ± 3.221.7 ± 0.9−113.6 ± 2.615.2 ± 0.6
DIV-LFS−61.8 ± 3.616.9 ± 1.1−75.0 ± 2.910.0 ± 1.3
DI-IQM−91.7 ± 6.118.9 ± 3.40.27330.7766−91.6 ± 4.226.1 ± 2.00.11890.0074
DII-IQM−50.8 ± 5.029.2 ± 4.00.66180.0833−57.2 ± 4.017.2 ± 3.40.25050.9400
DIII-IQM−106.4 ± 5.221.7 ± 1.90.75180.4405−92.6 ± 2.523.1 ± 1.50.00210.0014
DIV-IQM−48.9 ± 3.510.8 ± 2.80.03350.1183−59.2 ± 2.45.8 ± 1.20.00320.0299
DIII-N1325S−125.1 ± 1.920.7 ± 0.72.6 × 10−40.1545−106.3 ± 2.913.9 ± 0.70.13280.0644
DIII-A1330P−123.8 ± 3.423.6 ± 1.50.00180.8074−110.9 ± 2.815.8 ± 1.30.59920.9248
DIII-N1659A−97.0 ± 7.524.9 ± 2.80.20590.6136−85.0 ± 5.723.3 ± 1.50.00190.0015
DIV-N1659A−44.3 ± 2.810.6 ± 1.10.00870.0089−48.7 ± 2.314.2 ± 2.21.4 × 10−40.2343

Midpoints and slope factors from Boltzmann fits y/ymax = 1/(1 + exp[(V − V1/2)/k)] to steady-state activation and SSI data of ionic currents and fluorescence changes. Mean ± SEM of each parameter for sets of three to seven cells are shown. P-values from two sample t tests for mutants compare mutant parameters with corresponding WT parameters. Significant p-values <0.005 are in bold.