TABLE I.

Ca_V1 and Ca_V2 Inactivation Properties

Construct	ti300 (%)	ti2400 (%)	A1 (%)	τ1 (ms)	A2 (%)	τ2 (ms)	n
VDI
CaV1.2, β2a	2.2 ± 1.3	10.9 ± 2.6	20.9 ± 3.6	3,730 ± 670	—	—	12
CaV1.2 AAA, β2a	1.1 ± 0.6	11.9 ± 5.2	18.5 ± 7.5	3,290 ± 160	—	—	5
CaV1.2 6A, β2a	1.8 ± 0.6	16.1 ± 3.1	16.9 ± 1.6	1,880 ± 160	—	—	5
CaV1.2, β1	22.3 ± 1.8	62.4 ± 5.2	73.0 ± 5.7	1,150 ± 80	—	—	5
CaV1.2, β2b	4.8 ± 1.5	25.2 ± 2.1	44.5 ± 4.9	2,840 ± 630	—	—	8
CaV1.2, ssβ2a	7.1 ± 2.9	33.5 ± 7.7	43.3 ± 11.3	2,050 ± 510	—	—	6
CaV1.2	11.0 ± 3.0	ND	22.7 ± 3.9	455 ± 99	—	—	5
CaV1.2 HotA, β2a	8.9 ± 4.1	ND	23.6 ± 7.2	601 ± 211	—	—	5
CaV1.2 GGG, β2a	13.2 ± 2.5	ND	30.0 ± 6.6	489 ± 130	—	—	11
CaV1.2 6G, β2a	13.0 ± 5.6	ND	34.2 ± 3.4	485 ± 155	—	—	6
CaV1.2 GGG/HotA, β2a	8.9 ± 5.6	ND	21.7 ± 7.6	607 ± 277	—	—	7
CaV1.2 GGG	28.1 ± 3.6	ND	41.9 ± 3.8	255 ± 20	—	—	7
CaV1.2 GGG, β1	59.6 ± 4.3	ND	79.2 ± 3.7	202 ± 12	—	—	6
CaV1.2 GGG, β2b	42.8 ± 3.2	ND	66.0 ± 1.7	264 ± 14	—	—	6
CaV1.2 GGG, ssβ2a	47.7 ± 2.8	ND	72.0 ± 5.6	262 ± 14	—	—	5
CaV2.1, β2a	6.5 ± 1.2	ND	9.7 ± 1.5	308 ± 80	—	—	10
CaV2.1 GGG, β2a	36.9 ± 4.1	ND	59.3 ± 8.6	439 ± 42	9.2 ± 1.9	17.8 ± 2.2	6
CaV2.1 6G, β2a	39.5 ± 9.8	ND	45.3 ± 8.0	326 ± 31	14.5 ± 4.1	13.0 ± 2.3	7
CaV2.1 AAA, β2a	8.2 ± 1.2	ND	11.9 ± 1.6	283 ± 53	—	—	7
CaV2.1 6A, β2a	9.6 ± 1.5	ND	14.2 ± 2.2	311 ± 79	—	—	7
CaV2.1, β1	57.3 ± 4.3	ND	77.1 ± 7.1	340 ± 55	13.7 ± 2.9	43.9 ± 7.3	8
CaV2.1 GGG, β1	98.0 ± 5.1	ND	63.3 ± 2.3	10.1 ± 1.2	36.9 ± 4.1	94.1 ± 10.2	7
netCDI
CaV1.2, β2a	69.5 ± 2.6	ND	51.1 ± 2.7	20.3 ± 4.2	19.6 ± 2.7	96.8 ± 25.6	9
CaV1.2 AAA, β2a	72.3 ± 3.4	ND	53.3 ± 5.1	17.8 ± 1.3	20.4 ± 2.9	98.7 ± 25.9	5
CaV1.2 6A, β2a	60.5 ± 3.3	ND	40.4 ± 4.0	24.8 ± 1.0	21.8 ± 1.7	118 ± 13	5
CaV1.2, β1	75.3 ± 1.7	ND	57.0 ± 2.1	27.0 ± 1.8	23.1 ± 2.4	177 ± 32	5
CaV1.2, β2b	72.9 ± 1.7	ND	55.9 ± 3.2	25.4 ± 1.3	20.9 ± 1.0	165 ± 22	5
CaV1.2	36.6 ± 1.3	ND	34.2 ± 4.2	216 ± 55	12.1 ± 2.0	40.7 ± 13.0	6
CaV1.2 HotA, β2a	35.6 ± 4.2	ND	33.0 ± 4.3	239 ± 42	12.6 ± 1.9	45.3 ± 9.9	5
CaV1.2 GGG, β2a	43.7 ± 3.6	ND	37.2 ± 2.1	217 ± 16	16.9 ± 4.1	40.9 ± 5.4	8
CaV1.2 GGG/HotA, β2a	15.6 ± 6.2	ND	20.7 ± 6.1	258 ± 86	—	—	7
CaV1.2 6G, β2a	19.8 ± 5.4	ND	25.4 ± 8.9	214 ± 54	—	—	8
CaV1.2 GGG, β1	41.9 ± 3.8	ND	57.9 ± 3.9	350 ± 31	9.5 ± 4.1	56.2 ± 8.6	5
CaV1.2 GGG, β2b	42.2 ± 4.3	ND	50.4 ± 10.3	356 ± 92	18.4 ± 2.0	54.7 ± 10.5	4

Data are expressed as mean values ± SD. τ values were determined at a holding potential of +20 mV (see Materials and methods). t_i300 and t_i2400 denote percent inactivation at 300 and 2,400 ms, respectively. ND, a value not determined.