. 2005 Oct 20;90(2):443–453. doi: 10.1529/biophysj.105.072538

TABLE 2.

Single channel properties of wild-type and mutant RyR1s

Parameter	wild-type	D⁴⁸⁹⁹Q	E⁴⁹⁰⁰N	D⁴⁹³⁸N	D⁴⁹⁴⁵N	E⁴⁹⁵⁵Q
γ_K+ (pS)	801 ± 7(17)^†	164 ± 4(10)^†^*	505 ± 3(3)^†^*	520 ± 6(9)^*	737 ± 11(6)^*	812 ± 7(4)
at 0 mV (pA)	−2.8 ± 0.1(7)^†	−0.4 ± 0.1(4)^†^*	−2.0 ± 0.2(7)^†^*	−0.8 ± 0.1(4)^*	−2.0 ± 0.2(5)^*	−2.7 ± 0.2(3)
Erev (mV)	9.5 ± 0.2(6)^†	1.9 ± 0.1(4)^†^*	6.8 ± 0.4(5)^†^*	5.3 ± 0.3(4)^*	9.0 ± 0.6(5)	10.7 ± 0.7(3)
P_Ca/P_K	7.0^†	1.0^†	4.5^†	3.3	6.5	8.3
γ_K+(+Ry) (pS)	467 ± 19(8)	105 ± 2(9)^*	296 ± 4(9)^*	378 ± 8(6)^*	429 ± 7(9)	457 ± 5(4)
γ_K+(+Ry)/γ_K+(−Ry)	0.58	0.62	0.59	0.75^*	0.60	0.56
+ cis Neomycin at 70 mV
γ_{sub(+Ry,+Neo)}/γ_K+(+Ry)	0.16 ± 0.01(10)	0.37 ± 0.04(6)^*	0.23 ± 0.01(8)^*	0.49 ± 0.04(3)^*	0.47 ± 0.01(3)^*	0.15 ± 0.02 (3)
k′_on (μM⁻¹ ms⁻¹)	5.2 ± 0.8(7)	3.2 ± 0.7(3)	2.7 ± 0.3(3)	0.1 ± 0.1(3)^*	2.2 ± 0.2(4)^*	3.5 ± 0.3(3)
k_off (ms⁻¹)	0.5 ± 0.1(6)	1.4 ± 0.1(3)^*	0.5 ± 0.1(3)	0.8 ± 0.1(3)^*	2.1 ± 0.1(4)^*	0.3 ± 0.1(3)
K₅₀ (μM)	0.1	0.5	0.2	11.1	0.9	0.1
Z_total	1.1 ± 0.1(10)	1.0 ± 0.1(3)	1.0 ± 0.1(3)	0.4 ± 0.1(3)^*	1.2 ± 0.1(4)	1.1 ± 0.1(7)
+trans Neomycin at −60 mV
γ_{sub(+Ry,+Neo)}/γ_K+(+Ry)	0.39 ± 0.01(8)	^‡	^‡	0.50 ± 0.01(4)^*	0.38 ± 0.01(4)	0.41 ± 0.01(6)
k′_on (μM⁻¹ ms⁻¹)	1.6 ± 0.2(5)	^‡	^‡	0.7 ± 0.2(4)^*	0.6 ± 0.2(4)^*	0.7 ± 0.1(5)^*
k_off (ms⁻¹)	1.4 ± 0.4(5)	^‡	^‡	2.3 ± 0.2(4)^*	2.3 ± 0.2(4)^*	2.1 ± 0.1 (5)^*
K₅₀ (μM)	0.8	^‡	^‡	3.5	3.1	2.4
Z_total	−0.6 ± 0.1(4)	^‡	^‡	−0.7 ± 0.1(4)	−0.6 ± 0.1(4)	−0.6 ± 0.1(7)

p < 0.05 compared to wild-type.

^†

From Wang et al. (21).

^‡

Substate was not detected.

k_off was determined at 0.1 μM cis and 0.5 μM trans neomycin.