Fractional magnitudes of time constants for ionic current, gating current, and fluorescence during the onset of SI
| Channel variant (measured parameter) | AF | AI | AS | C | n |
| WT (I) | 0.13 ± 0.01 | 0.11 ± 0.01 | 0.51 ± 0.06 | 0.25 ± 0.05 | 14 |
| WT (Q) (2 µM TTX) | 0.13 ± 0.01 | 0.03 ± 0.01 | 0.35 ± 0.03 | 0.49 ± 0.03 | 4 |
| DI (F) | 0.25 ± 0.02 | 0.17 ± 0.03 | 0.28 ± 0.03 | 0.30 ± 0.04 | 6 |
| DII (F) | 0.23 ± 0.06 | 0.27 ± 0.04 | 0.27 ± 0.02 | 0.23 ± 0.06 | 6 |
| DIII (F) | 0.28 ± 0.05 | 0.17 ± 0.05 | 0.26 ± 0.06 | 0.30 ± 0.05 | 8 |
| DIV (F) | 0.29 ± 0.03 | 0.08 ± 0.04 | 0.16 ± 0.03 | 0.46 ± 0.03 | 6 |
| Channel variant (measured parameter) | AF | AI | AS | C | n |
| WT (I) | 0.13 ± 0.01 | 0.11 ± 0.01 | 0.51 ± 0.06 | 0.25 ± 0.05 | 14 |
| WT (Q) (2 µM TTX) | 0.13 ± 0.01 | 0.03 ± 0.01 | 0.35 ± 0.03 | 0.49 ± 0.03 | 4 |
| DI (F) | 0.25 ± 0.02 | 0.17 ± 0.03 | 0.28 ± 0.03 | 0.30 ± 0.04 | 6 |
| DII (F) | 0.23 ± 0.06 | 0.27 ± 0.04 | 0.27 ± 0.02 | 0.23 ± 0.06 | 6 |
| DIII (F) | 0.28 ± 0.05 | 0.17 ± 0.05 | 0.26 ± 0.06 | 0.30 ± 0.05 | 8 |
| DIV (F) | 0.29 ± 0.03 | 0.08 ± 0.04 | 0.16 ± 0.03 | 0.46 ± 0.03 | 6 |
First, SI of ionic current at +45 mV was fit using three exponentials with time constants for fast, intermediate, and slow components: τF = 1.8 ± 0.2 s, τI = 13.1 ± 1.1 s, and τS = 195 ± 33 s. Because the three time constants span the time domains of our protocol, they can be held constant and used to describe data from ionic, gating, and fluorescence measurements by varying the fractional magnitude of each component (Fig. S1). The table shows the fractional magnitude of each component for all studies in this article. n, the number of cells studied; WT, wild-type channel; DI, DII, DIII, and DIV indicate channels with the single site changes DI-S216C, DII-S660C, DIII-L115C, and DIV-S1436C, respectively; I, current assessed after subtraction of Q; F indicates a fit to fluorescence.