TABLE 1

Activation, inactivation kinetics, and current densities of Na_v1.4 wild-type (WT) and mutant channels

The fitted values (± S.E. of the fit) for voltage dependence of activation (E_0.5, k_E) and fast inactivation (h_0.5, k_h) were determined as described in Fig. 2, A and B. For current densities (mean ± S.E.M.), peak currents at +60 mV were measured and divided by the membrane capacitance estimated by the acquisition software.
Channel	E_0.5	k_E	h_0.5	k_h	Current Density
		mV				pA/pF
WT	-34.7 ± 1.7	6.8 ± 0.7	-76.9 ± 2.0	5.7 ± 0.2	253 ± 51
	(n = 7)	(n = 7)	(n = 8)	(n = 8)
L1280A	-16.4 ± 2.1	9.9 ± 0.5	-83.8 ± 1.2	6.0 ± 0.2	74 ± 10
	(n = 5)	(n = 5)	(n = 6)	(n = 6)
L1280C	-24.9 ± 0.8	8.4 ± 0.4	-86.3 ± 1.7	5.8 ± 0.3	210 ± 73
	(n = 7)	(n = 7)	(n = 6)	(n = 6)
L1280D	-27.9 ± 3.1	11.7 ± 0.6	-84.2 ± 1.3	7.5 ± 0.4	40 ± 10
	(n = 7)	(n = 7)	(n = 9)	(n = 9)
L1280E	-19.5 ± 0.9	10.1 ± 0.6	-90.5 ± 1.8	6.8 ± 0.2	50 ± 11
	(n = 5)	(n = 5)	(n = 5)	(n = 5)
L1280K	-20.4 ± 2.2	8.3 ± 0.5	-88.4 ± 2.1	6.5 ± 0.3	99 ± 17
	(n = 7)	(n = 7)	(n = 7)	(n = 7)
L1280N	-6.5 ± 1.4	12.8 ± 0.8	-87.4 ± 2.0	6.6 ± 0.3	174 ± 35
	(n = 7)	(n = 7)	(n = 5)	(n = 5)
L1280Q	-15.5 ± 2.6	11.6 ± 1.3	-83.6 ± 1.9	6.1 ± 0.2	60 ± 11
	(n = 8)	(n = 8)	(n = 6)	(n = 6)
L1280R	-13.0 ± 3.9	14.5 ± 1.4	-93.1 ± 1.2	7.4 ± 0.3	50 ± 12
	(n = 7)	(n = 7)	(n = 6)	(n = 6)
L1280T	-20.7 ± 1.3	10.0 ± 0.8	-88.4 ± 1.3	6.5 ± 0.3	127 ± 29
	(n = 8)	(n = 8)	(n = 7)	(n = 7)
L1280W	-28.8 ± 1.2	9.1 ± 0.6	-86.1 ± 1.7	6.0 ± 0.4	109 ± 24
	(n = 8)	(n = 8)	(n = 8)	(n = 8)
N343E	-43.7 ± 1.2	7.4 ± 0.4	-72.6 ± 0.9	4.9 ± 0.3	108 ± 26
	(n = 6)	(n = 6)	(n = 5)	(n = 5)
N434Q	-36.6 ± 1.6	8.5 ± 0.3	-67.0 ± 1.8	6.3 ± 0.4	328 ± 67
	(n = 7)	(n = 7)	(n = 6)	(n = 6)