Kinetic analysis of AChRs with mutations in the β -, δ -, and ϵ -subunits
| AChR | k+1 | k−1 | K1 (μm) | k+2 | k−2 | K2 (μm) | β 1 | α 1 | θ1 | β 2 | α 2 | θ2 | k+b | k−b | KB (mm) | ΔG° (kcal/mol) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wild type | 271 ± 16 | 7190 ± 545 | 26 | 192 ± 6 | 19,300 ± 309 | 101 | 67 ± 8 | 2190 ± 160 | 0.03 ± 0.0043 | 43,700 ± 999 | 1650 ± 32 | 26.5 ± 0.79 | 26 ± 1 | 113,000 ± 1690 | 4.3 | - |
| Mutant | ||||||||||||||||
| βF135L | 437 ± 51 | 6570 ± 849 | 15 | 201 ± 6.6 | 21,600 ± 424 | 107 | NA | NA | 53,000 ±1380 | 2640 ± 65 | 20 ± 0.72 | 19 ± 1 | 94,700 ± 2040 | 5.0 | 0.16 ± 0.047 | |
| βF137L | 296 ± 28 | 7230 ± 823 | 24 | 186 ± 8 | 23,100 ± 481 | 124 | 148 ± 20 | 2180 ± 186 | 0.068 ± 0.011 | 37,000 ± 963 | 1230 ± 25 | 30 ± 0.99 | 21 ± 1 | 105,000 ± 1640 | 5.0 | −0.07 ± 0.045 |
| βK221Q | 269 ± 42 | 3320 ± 586 | 12 | 135 ± 4 | 21,800 ± 536 | 161 | 45 ± 11 | 2160 ± 201 | 0.021 ± 0.0055 | 41,800 ± 963 | 1420 ± 30 | 29 ± 0.91 | 18 ± 1 | 112,000 ± 1820 | 6.2 | −0.06 ± 0.043 |
| βI284F | 237 ± 23 | 5400 ± 579 | 20 | 165 ± 6 | 22,200 ± 512 | 134 | 150 ± 19 | 3070 ± 208 | 0.049 ± 0.0070 | 30,200 ± 648 | 2480 ± 39 | 12 ± 0.32 | 21 ± 1 | 102,000 ± 2010 | 4.9 | 0.46 ± 0.040 |
| δF137L | 416 ± 156 | 10,400 ± 4020 | 25 | 243 ± 17 | 23,500 ±1230 | 97 | NA | NA | 11,600 ± 216 | 5260 ± 56 | 2.2 ± 0.047 | 19 ± 1 | 90,700 ± 2610 | 4.8 | 1.46 ± 0.037 | |
| δF139L | 334 ± 48 | 4440 ± 738 | 13 | 132 ± 4.6 | 25,200 ± 614 | 191 | 49 ± 13 | 2970 ± 239 | 0.016 ± 0.0044 | 31,000 ± 849 | 2890 ± 55 | 11 ± 0.37 | 18 ± 1 | 104,000 ± 2520 | 5.8 | 0.53 ± 0.045 |
| δK224Q | 222 ± 16 | 2220 ± 241 | 10 | 172 ± 6.2 | 11,400 ± 220 | 66 | NA | NA | NA | 67,000 ±1500 | 1500 ± 43 | 44.5 ± 1.56 | 20 ± 1 | 115,000 ± 2390 | 5.8 | −0.31 ± 0.046 |
| δL287F | 110 ± 13 | 1300 ± 190 | 12 | 111 ± 5.5 | 20,500 ± 490 | 185 | NA | NA | NA | 43,900 ±1400 | 870 ± 24 | 50.4 ± 2.52 | 18 ± 1 | 115,000 ± 2400 | 6.4 | −0.38 ± 0.056 |
| ϵF135L | 420 ± 140 | 7200 ± 2500 | 17 | 186 ± 9.3 | 22,200 ± 800 | 119 | NA | NA | NA | 12,500 ± 210 | 4300 ± 40 | 2.9 ± 0.060 | 17 ± 1 | 100,000 ± 2600 | 5.9 | 1.30 ± 0.036 |
| ϵF137L | 331 ± 33 | 5840 ± 708 | 18 | 155 ± 5.4 | 19,200 ± 398 | 124 | 101 ± 14 | 2121 ± 158 | 0.048 ± 0.0076 | 33,400 ± 771 | 1650 ± 29 | 20 ± 0.58 | 22 ± 1 | 109,000 ± 2090 | 5.0 | 0.16 ± 0.042 |
| ϵK219Q | 140 ± 8.8 | 1200 ± 110 | 9 | 170 ± 5.1 | 10,700 ± 180 | 63 | NA | NA | NA | 59,000 ±1010 | 1550 ± 33 | 38 ± 1.02 | 21 ± 1 | 114,000 ± 2000 | 5.4 | −0.21 ± 0.040 |
| ϵL283F | 181 ± 15 | 878 ± 93 | 4.9 | 122 ± 2.8 | 16,000 ± 239 | 131 | NA | NA | 53,600 ± 1080 | 1470 ± 30 | 36 ± 1.03 | 19 ± 1 | 108,000 ± 2060 | 5.7 | −0.19 ± 0.042 | |