Table 1. Biophysical parameters of Na v... | Rockefeller University Press

Table 1.

Biophysical parameters 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
Activation	V1/2 (mV)	−25.5 ± 0.6	−22.9 ± 0.9^a	−28.3 ± 1.0	−28.1 ± 1.2	−32.9 ± 0.6	−31.4 ± 0.6^b
	k	5.9 ± 0.3	6.7 ± 0.3^a	6.0 ± 0.3	6.3 ± 0.4	6.5 ± 0.2	7.0 ± 0.2
	n	13	13	12	12	10	10
Fast inactivation	V₁1/2 (mV)	−67.2 ± 1.0	−62.5 ± 1.8^a	−64.7 ± 1.3	−68.3 ± 1.3^a	−58.4 ± 1.4	−57.8 ± 1.3
	k₁	4.7 ± 0.3	4.4 ± 0.1	4.9 ± 0.3	4.9 ± 0.4	4.6 ± 0.5	4.3 ± 0.1
	A₁	0.72 ± 0.03	0.73 ± 0.01	0.64 ± 0.02	0.69 ± 0.02^a	0.75 ± 0.03	0.74 ± 0.03
	V₂1/2 (mV)	−94.7 ± 2.2	−85.4 ± 2.3^a	−87.8 ± 2.3	−94.3 ± 1.9	−82.9 ± 2.8	−83.9 ± 2.5
	k₂	4.4 ± 0.8	3.9 ± 0.7	5.8 ± 0.9	5.1 ± 0.9	3.5 ± 0.8	6.3 ± 1.3^a
	A₂	0.28 ± 0.04	0.27 ± 0.01	0.35 ± 0.02	0.32 ± 0.02	0.25 ± 0.03	0.26 ± 0.03
	n	10	9	9	8	8	9
Recovery from inactivation	τ₁ (ms)	10.1 ± 2.10	8.80 ± 1.40	5.90 ± 1.20	23.8 ± 8.80^c	26.8 ± 5.30	13.2 ± 3.36^a
	A₁	0.32 ± 0.04	0.48 ± 0.07^a	0.18 ± 0.03	0.33 ± 0.07^a	0.48 ± 0.08	0.30 ± 0.05^a
	τ₂ (ms)	46.3 ± 4.50	47.7 ± 6.30	175 ± 14.8	141 ± 13.9^a	128 ± 20.8	53.1 ± 7.10^d
	A₂	0.47 ± 0.04	0.33 ± 0.07	0.68 ± 0.04	0.49 ± 0.07^a	0.36 ± 0.07	0.57 ± 0.05^a
	n	13	9	12	12	10	9

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
Activation	V1/2 (mV)	−25.5 ± 0.6	−22.9 ± 0.9^a	−28.3 ± 1.0	−28.1 ± 1.2	−32.9 ± 0.6	−31.4 ± 0.6^b
	k	5.9 ± 0.3	6.7 ± 0.3^a	6.0 ± 0.3	6.3 ± 0.4	6.5 ± 0.2	7.0 ± 0.2
	n	13	13	12	12	10	10
Fast inactivation	V₁1/2 (mV)	−67.2 ± 1.0	−62.5 ± 1.8^a	−64.7 ± 1.3	−68.3 ± 1.3^a	−58.4 ± 1.4	−57.8 ± 1.3
	k₁	4.7 ± 0.3	4.4 ± 0.1	4.9 ± 0.3	4.9 ± 0.4	4.6 ± 0.5	4.3 ± 0.1
	A₁	0.72 ± 0.03	0.73 ± 0.01	0.64 ± 0.02	0.69 ± 0.02^a	0.75 ± 0.03	0.74 ± 0.03
	V₂1/2 (mV)	−94.7 ± 2.2	−85.4 ± 2.3^a	−87.8 ± 2.3	−94.3 ± 1.9	−82.9 ± 2.8	−83.9 ± 2.5
	k₂	4.4 ± 0.8	3.9 ± 0.7	5.8 ± 0.9	5.1 ± 0.9	3.5 ± 0.8	6.3 ± 1.3^a
	A₂	0.28 ± 0.04	0.27 ± 0.01	0.35 ± 0.02	0.32 ± 0.02	0.25 ± 0.03	0.26 ± 0.03
	n	10	9	9	8	8	9
Recovery from inactivation	τ₁ (ms)	10.1 ± 2.10	8.80 ± 1.40	5.90 ± 1.20	23.8 ± 8.80^c	26.8 ± 5.30	13.2 ± 3.36^a
	A₁	0.32 ± 0.04	0.48 ± 0.07^a	0.18 ± 0.03	0.33 ± 0.07^a	0.48 ± 0.08	0.30 ± 0.05^a
	τ₂ (ms)	46.3 ± 4.50	47.7 ± 6.30	175 ± 14.8	141 ± 13.9^a	128 ± 20.8	53.1 ± 7.10^d
	A₂	0.47 ± 0.04	0.33 ± 0.07	0.68 ± 0.04	0.49 ± 0.07^a	0.36 ± 0.07	0.57 ± 0.05^a
	n	13	9	12	12	10	9

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

P < 0.05.

P < 0.0001.

P < 0.001.

P < 0.01.

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