Supplementary TableS1. Kinetic analysis of AChRs with mutations in the -subunit.

-Subunit Mutations / ACh Concentration
Range (M) / k+1 / k-1 / K1
(M) / K+2 / k-2 / K2
(M) /  /  / 
(/)
Wild-type / 3-1,000 / 271
(16)* / 7,190
(545) / 26.5 / 192
(6) / 19,300
(309) / 101 / 43,700
(999) / 1,650
(32) / 26.5
(0.80)
E45A / 10-1,000 / 296
(37) / 5,300
(770) / 17.9 / 173
(6) / 19,500
(447) / 113 / 28,900
(504) / 13,700
(153) / 2.11
(0.04)
E45K / 3-1,000 / 312
(54) / 645
(154) / 2.07 / 263
(17) / 1,480
(67) / 5.63 / 5,110
(53) / 22,800
(142) / 0.224
(0.003)
E45R / 1-1,000 / 484
(69) / 821
(54) / 1.70 / 337
(24) / 1,400
(55) / 4.15 / 21,200
(172) / 5,080
(44) / 4.17
(0.04)
V46A / 30-1,000 / 111
(58) / 3,100
(1,630) / 27.9 / 55
(30) / 9,490
(4,990) / 173 / 155
(5) / 2,740
(53) / 0.057
(0.002)
H134A / 3-1,000 / 221
(11) / 2,260
(307) / 10.2 / 85
(4) / 21,700
(693) / 255 / 10,200
(398) / 1,600
(22) / 6.38
(0.27)
E175Q / 3-1,000 / 178
(30) / 2,430
(482) / 13.7 / 137
(6) / 25,600
(747) / 187 / 14,100
(426) / 1,770
(23) / 7.97
(0.26)
W176F / 3-1,000 / 255
(40) / 3,010
(531) / 11.8 / 103
(4) / 18,300
(355) / 178 / 37,100
(1,140) / 1,550
(36) / 23.9
(0.92)
R209Q / 3-100 / 21
(4) / 58
(16) / 2.76 / 102
(10) / 8,200
(751) / 80 / 9,430
(750) / 15,900
(600) / 0.59
(0.05)
S269L / 0.3-30 / 525
(294) / 306
(221) / 0.58 / 246
(30) / 2,120
(145) / 8.62 / 81,200
(1,590) / 979
(33) / 82.9
(3.24)
A270L / 3-1,000 / 212
(29) / 3050
(465) / 14.4 / 113
(4) / 16,800
(398) / 149 / 34,300
(1,160) / 1160
(29) / 29.6
(1.26)
V271A / 3-1,1000 / 199
(27) / 2,370
(348) / 11.9 / 87
(3) / 18,500
(418) / 212 / 29,100
(903) / 1,150
(24) / 25.3
(0.94)
P272G / 30-1,000 / 31
(19) / 895
(653) / 28.9 / 115
(26) / 13,400
(2,440) / 117 / 1,260
(29) / 7,410
(72) / 0.17
(0.004)
P272S / 3-1,000 / 306
(125) / 2,800
(1,220) / 9.15 / 77
(3) / 17,600
(561) / 229 / 11,900
(387) / 845
(12) / 14.1
(0.50)
L273G / 3-1,000 / 137
(13) / 1,980
(231) / 14.5 / 130
(6) / 13,000
(310) / 100 / 45,200
(1,210) / 1,860
(49) / 24.3
(0.90)
E45R+R209E / 3-30 / 546
(85) / 1,880
(683) / 3.44 / 980
(178) / 3,930
(333) / 4.0 / 56,000
(2,450) / 2,860
(148) / 19.6
(1.37)
E45R+R209Q / 3-1,000 / 184
(18) / 2,170
(273) / 11.8 / 216
(9) / 8,730
(251) / 40 / 41,300
(883) / 2,160
(48) / 19.1
(0.58)
E45A+V46A / 100-1,000 / ND / ND / - / ND / ND / - / 78
(1) / 16,800
(240) / 0.005
(0.0001)
E45A+S269L / 1-1,000 / 183
(17) / 629
(72) / 3.44 / 194
(8) / 5,450
(130) / 28.1 / 74,800
(1,390) / 5,430
(164) / 13.8
(0.49)
E45A+P272G / 30-1,000 / 111
(27) / 1,610
(712) / 14.5 / 79
(19) / 13,000
(2,860) / 165 / 817
(40) / 19,500
(218) / 0.042
(0.002)
V46A+S269L / 3-1,000 / 239
(84) / 950
(349) / 3.97 / 94
(4) / 18,900
(590) / 201 / 5,870
(146) / 1,970
(17) / 2.98
(0.08)
V46A+P272G / 300-1,000 / ND / ND / - / ND / ND / - / 38
(1) / 6,750
(178) / 0.006
(0.0002)
S269L+P272G / 10-1,000 / 200 / 131
(87) / 0.67 / 82
(3) / 5,630
(184) / 68.7 / 5,970
(88) / 9,070
(79) / 0.66
(0.01)
E45A+V46A+S269L / 10-1,000 / 65
(22) / 1,640
(636) / 25.2 / 147
(18) / 30,700
(2,954) / 209 / 3,100
(96) / 9,630
(88) / 0.32
(0.01)
E45A+V46A+P272G / 1,000 / ND / ND / - / ND / ND / - / 61
(2) / 11,300
(327) / 0.005
(0.0002)
V46A+S269L+P272G / 300-1,000 / ND / ND / - / ND / ND / - / 105
(4) / 9,170
(150) / 0.011
(0.0003)

Rate constants and *standard errors were derived from global fitting of a mechanistic description of receptor activation to data obtained over the indicated ACh concentration ranges (Methods). Units are M-1s-1 for the association rate constants, s-1 all others. ND indicates the fitted parameter was not defined.