Table 1.

Fractional magnitudes of time constants for L689I ionic current, gating current, and fluorescence during the onset of SI

Channel variant (measured parameter)	AF	AI	AS	C	n
L689I (I)	0.10 ± 0.01	0.06 ± 0.02a	0.54 ± 0.04	0.30 ± 0.05	7
L689I (Q) (2 µM TTX)	0.11 ± 0.04	0.05 ± 0.02	0.20 ± 0.05	0.63 ± 0.04	5
L689I DI (F)	0.15 ± 0.02a	0.12 ± 0.05	0.29 ± 0.06	0.45 ± 0.03a	7
L689I DII (F)	0.12 ± 0.05	0.06 ± 0.03a	0.21 ± 0.03	0.61 ± 0.05a	4
L689I DIII (F)	0.26 ± 0.07	0.15 ± 0.06	0.31 ± 0.04	0.28 ± 0.09	8
L689I DIV (F)	0.28 ± 0.08	0.04 ± 0.02	0.26 ± 0.13	0.42 ± 0.12	6

First, SI of ionic current at +45 mV was fit using three exponentials with time constants for fast, intermediate, and slow components: τ_F = 1.8 ± 0.2 s, τ_I = 13.1 ± 1.1 s, and τ_S = 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. The table shows the fractional magnitude of each component for all studies in this paper. n, the number of cells studied; I, current assessed after subtraction of Q; F indicates a fit to fluorescence; DI, DII, DIII, and DIV indicate L689I channels that also carry the single site changes DI-S216C, DII-S660C, DIII-L115C, and DIV-S1436C, respectively.

^aParameter is significantly different from WT.