Table 2.

Electrophysiological Properties of S2 Segment Trp Mutant Channels

Construct	Vo	z	ΔG o	ΔΔG o	t o	τd
	mv		kcal/mol	kcal/mol	ms	ms
WT	−19 ± 3	2.6 ± 0.3	−1.2 ± 0.3	—	4.5 ± 0.3	1.1 ± 0.2
V311W	−9 ± 1	1.8 ± 0.1	−0.4 ± 0.1	0.8	5.8 ± 0.3	1.0 ± 0.1
M312W	47 ± 13	1.2 ± 0.1	1.3 ± 0.4	2.5	2.9 ± 0.4	0.7 ± 0.1
N313W	−51 ± 1	4.1 ± 0.4	−4.8 ± 0.6	−3.6	8.0 ± 0.7	3.2 ± 0.3
V314W	−14 ± 3	1.9 ± 0.2	−0.6 ± 0.2	0.6	4.0 ± 0.3	1.5 ± 0.2
I315W	−53 ± 1	5.2 ± 0.6	−6.3 ± 0.9	−5.1	23.1 ± 1.7	12.1 ± 0.9
D316W	38 ± 14	1.1 ± 0.1	1.0 ± 0.3	2.2	<3.0	<1.0
I317W	−12 ± 2	2.3 ± 0.1	−0.7 ± 0.1	0.5	6.8 ± 1.0	1.5 ± 0.1
I318W	−14 ± 3	2.1 ± 0.3	−0.7 ± 0.2	0.5	8.2 ± 1.1	2.2 ± 0.3
A319W	1 ± 4	2.4 ± 0.2	0.1 ± 0.2	1.3	21.0 ± 1.7	3.7 ± 1.0
I320W	−13 ± 3	2.4 ± 0.3	−0.8 ± 0.2	0.4.	5.7 ± 0.3	1.7 ± 0.1
I321W	−31 ± 2	2.5 ± 0.2	−1.8 ± 0.3	−0.6	14.5 ± 2.6	2.6 ± 0.2
P322W	−22 ± 2	2.4 ± 0.2	−1.2 ± 0.2	0.0	51.5 ± 3.2	4.7 ± 0.7
Y323W	−15 ± 2	1.9 ± 0.2	−0.7 ± 0.1	0.5	5.1 ± 3.2	4.7 ± 0.7
F324W	−15 ± 2	1.9 ± 0.2	−0.7 ± 0.1	0.5	5.1 ± 0.5	1.6 ± 0.4
I325W	−17 ± 3	3.2 ± 0.4	−1.2 ± 0.3	0.0	34.2 ± 1.5	1.6 ± 0.4
T326W	−25 ± 1	4.7 ± 0.2	−2.7 ± 0.2	−1.5	24.3 ± 1.7	4.4 ± 0.6
L327W	−20 ± 3	3.6 ± 0.9	−1.7 ± 0.6	−0.5	13.3 ± 1.7	2.0 ± 0.5
A328W	−22 ± 3	3.1 ± 0.6	−1.6 ± 0.5	−0.4	5.4 ± 0.4	1.3 ± 0.2
T329W	−58 ± 1	5.9 ± 0.6	−7.9 ± 1.0	−6.7	15.3 ± 2.0	6.7 ± 0.8
V330W	−31 ± 2	5.4 ± 0.5	−4.0 ± 0.6	−2.8	11.9 ± 1.0	2.9 ± 0.5
V331W	−28 ± 3	4.7 ± 0.9	−3.1 ± 0.9	−1.9	12.2 ± 1.9	2.2 ± 0.3
A332W	−33 ± 1	4.6 ± 0.3	−3.5 ± 0.3	−2.1	12.5 ± 2.5	2.3 ± 0.2

Parameters are as described in Table . The expression level of D316W was very low and the opening and closing kinetics were too fast to measure accurately.