Table 2. Biophysical parameters of slow... | Rockefeller University Press

Table 2.

Biophysical parameters of slow inactivation of Na_v1.1 WT, R859H, and R865G sodium ion channels measured at 37 and 40°C

Gating process	Parameter	Na_v1.1 WT 37°C	Na_v1.1 WT 40°C	R859H 37°C	R859H 40°C	R865G 37°C	R865G 40°C
Entry into slow inactivation	τ₁ (ms)	35.8 ± 9.30	42.6 ± 9.80	64.3 ± 16.2	69.3 ± 14.3	50.2 ± 10.8	36.4 ± 9.00
	A₁	0.14 ± 0.03	0.16 ± 0.04	0.29 ± 0.06	0.24 ± 0.06	0.32 ± 0.08	0.25 ± 0.08
	τ₂ (ms)	290 ± 26.3	217 ± 19.8^a	302 ± 28.3	216 ± 26.5^a	196 ± 23.1	122 ± 9.50^a
	A₂	0.61 ± 0.05	0.61 ± 0.04	0.58 ± 0.08	0.62 ± 0.06	0.55 ± 0.09	0.56 ± 0.07
	I_residual (%)	26 ± 4	22 ± 2	14 ± 3	14 ± 3	13 ± 4	19 ± 4
	n	8	10	9	12	9	10
Slow inactivation	V1/2 (mV)	−54.3 ± 1.0	−57.9 ± 1.1^a	−56.3 ± 1.2	−59.3 ± 0.7^a	−64.3 ± 0.9	−65.6 ± 0.8
	k	6.9 ± 0.4	6.9 ± 0.5	7.5 ± 0.3	7.6 ± 0.4	6.6 ± 0.3	6.3 ± 0.5
	n	11	10	10	7	7	7
Recovery from slow inactivation	τ₁ (ms)	11.2 ± 1.80	11.8 ± 1.90	18.7 ± 7.70	25.4 ± 5.10	22.5 ± 2.80	21.3 ± 3.9
	A₁	0.57 ± 0.06	0.65 ± 0.07	0.23 ± 0.03	0.31 ± 0.07	0.52 ± 0.07	0.59 ± 0.07
	τ₂ (ms)	90.7 ± 8.80	86.0 ± 14.6	178 ± 29.2	131 ± 13.8^a	124 ± 8.00	111 ± 17.8
	A₂	0.49 ± 0.05	0.41 ± 0.07	0.79 ± 0.02	0.68 ± 0.08	0.48 ± 0.06	0.40 ± 0.07
	n	10	10	8	9	7	10

Gating process	Parameter	Na_v1.1 WT 37°C	Na_v1.1 WT 40°C	R859H 37°C	R859H 40°C	R865G 37°C	R865G 40°C
Entry into slow inactivation	τ₁ (ms)	35.8 ± 9.30	42.6 ± 9.80	64.3 ± 16.2	69.3 ± 14.3	50.2 ± 10.8	36.4 ± 9.00
	A₁	0.14 ± 0.03	0.16 ± 0.04	0.29 ± 0.06	0.24 ± 0.06	0.32 ± 0.08	0.25 ± 0.08
	τ₂ (ms)	290 ± 26.3	217 ± 19.8^a	302 ± 28.3	216 ± 26.5^a	196 ± 23.1	122 ± 9.50^a
	A₂	0.61 ± 0.05	0.61 ± 0.04	0.58 ± 0.08	0.62 ± 0.06	0.55 ± 0.09	0.56 ± 0.07
	I_residual (%)	26 ± 4	22 ± 2	14 ± 3	14 ± 3	13 ± 4	19 ± 4
	n	8	10	9	12	9	10
Slow inactivation	V1/2 (mV)	−54.3 ± 1.0	−57.9 ± 1.1^a	−56.3 ± 1.2	−59.3 ± 0.7^a	−64.3 ± 0.9	−65.6 ± 0.8
	k	6.9 ± 0.4	6.9 ± 0.5	7.5 ± 0.3	7.6 ± 0.4	6.6 ± 0.3	6.3 ± 0.5
	n	11	10	10	7	7	7
Recovery from slow inactivation	τ₁ (ms)	11.2 ± 1.80	11.8 ± 1.90	18.7 ± 7.70	25.4 ± 5.10	22.5 ± 2.80	21.3 ± 3.9
	A₁	0.57 ± 0.06	0.65 ± 0.07	0.23 ± 0.03	0.31 ± 0.07	0.52 ± 0.07	0.59 ± 0.07
	τ₂ (ms)	90.7 ± 8.80	86.0 ± 14.6	178 ± 29.2	131 ± 13.8^a	124 ± 8.00	111 ± 17.8
	A₂	0.49 ± 0.05	0.41 ± 0.07	0.79 ± 0.02	0.68 ± 0.08	0.48 ± 0.06	0.40 ± 0.07
	n	10	10	8	9	7	10

Slow gating parameters of the WT Na_v1.1 channel and the two mutants R859H and R865G at 37 and 40°C. Shown are the entry into inactivation and the voltage dependence of and the recovery from slow inactivation. Ion channel slow gating parameters at 40°C that significantly differ from the values obtained at 37°C are indicated as follows:

P < 0.05.

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