Table 1.

V₅₀ and slope factor values from single Boltzmann fits of the GV relations

Channel	n	pH 6		pH 7		pH 8
		V50	s	V50	s	V50	s
		mV	mV	mV	mV	mV	mV
Kv12.2
WT	4	5 ± 1	20.8 ± 0.5	−13 ± 3	23.4 ± 0.6	−29 ± 3	24 ± 1
Kv12.1
WTa	6	−35 ± 2	11 ± 1	−65 ± 2	11 ± 1	−76 ± 2	12 ± 1
D261A	4	−5 ± 2	10 ± 1	−37 ± 2	10.3 ± 0.5	−46 ± 1	10.2 ± 0.4
D261E	6	−56 ± 2	12.3 ± 0.3	−109 ± 1	11.2 ± 0.5	−135 ± 2	10.2 ± 0.5
E265A	4	−28.7 ± 0.9	9.6 ± 0.4	−39 ± 1	9.6 ± 0.2	−42 ± 1	10.4 ± 0.2
E265D	7	−52 ± 1	11.3 ± 0.3	−72 ± 1	12.7 ± 0.8	−89 ± 2	13.2 ± 0.7
D314A	8	44 ± 2	16.8 ± 0.9	53 ± 2	15.1 ± 0.7	45 ± 2	14.6 ± 0.9
D314E	8	−70 ± 2	13 ± 1	−69 ± 2	14 ± 1	−64 ± 2	11.4 ± 0.9
H328A	8	−42 ± 3	13.9 ± 0.8	−62 ± 1	12.8 ± 0.6	−78 ± 0.5	12.6 ± 0.3
H328R	6	0 ± 1	16 ± 1	−4 ± 1	14.2 ± 0.6	−6 ± 1	14.4 ± 0.6
H328W	6	−18 ± 2	14.2 ± 0.8	−32 ± 3	15.4 ± 0.4	−37 ± 2	14.7 ± 0.5
H328R D261A	7	14 ± 1	12.0 ± 0.3	−11 ± 3	16.5 ± 0.9	−20 ± 3	17.8 ± 0.8
Kv10.2
WT	11	−24 ± 2	22 ± 1	−71 ± 3	18.0 ± 0.3	−95 ± 3	15.8 ± 0.2
D251N	10	14 ± 2	21.5 ± 0.4	−32 ± 2	20.8 ± 0.4	−57 ± 3	21.9 ± 0.5
D255C	4	−9 ± 7	34 ± 2	−25 ± 8	38 ± 3	−31 ± 6	38 ± 3
D304N	8	−23 ± 2	18.0 ± 0.7	−35 ± 2	17.1 ± 0.5	−37 ± 2	17.5 ± 0.7
D304E	9	−1 ± 3	28 ± 1	−38 ± 2	20.1 ± 0.4	−75 ± 2	13.7 ± 0.3
Kv11.1
WT	5	−16.4 ± 0.8	7.1 ± 0.3	−26.9 ± 0.5	7.7 ± 0.3	−28.8 ± 0.4	8.2 ± 0.5
D456C 1 mM Ca2+	9	34 ± 2	13.1 ± 0.6	12 ± 1	13.5 ± 0.8	1 ± 1	15.9 ± 0.7
D460C 1 mM Ca2+	9	24 ± 1	10.7 ± 0.4	10 ± 1	12.5 ± 0.4	4 ± 1	13.0 ± 0.7
D509C 1 mM Ca2+	6	25 ± 2	12.6 ± 0.3	17 ± 2	12.9 ± 0.3	11 ± 1	13.7 ± 0.3
WT 50 µM Ca2+b	7	−7 ± 1	14.6 ± 0.9	ND	ND	−54 ± 1	9.2 ± 0.9
D456C 50 µM Ca2+b	6	37 ± 1	11.5 ± 0.4	ND	ND	4 ± 2	14.7 ± 0.7
D460C 50 µM Ca2+b	4	26 ± 3	10.6 ± 0.3	ND	ND	6 ± 4	19 ± 1
D509C 50 µM Ca2+b	6	25 ± 3	15.3 ± 0.7	ND	ND	6 ± 4	16.1 ± 0.3

n, number of measurements; V₅₀, half-maximal activation voltage; s, slope factor.

^aValues reported for 8-s test depolarization steps as shown in Fig. 4.

^bThere are no pH 7 values listed because we only thoroughly tested pH 6 and 8 to see whether this shift was changed in low Ca²⁺.