Table 1.
Kinetic and thermodynamic binding parameters for the 3.L2 and M15 TCR interactions with pMHC ligands. Kinetic values were determined using surface plasmon resonance and equilibrium binding analysis, and thermodynamic parameters were calculated with van’t Hoff analysis of KD values obtained with SPR over the temperature range of 10-30°C. Values are presented as mean ± standard deviation of two to six experiments.
| 3.L2-Hb/I-Ek | M15-Hb/I-Ek | M15-Q72/I-Ek | M15-D73/I-Ek | 3.L2-D73/Ek dimer | |
|---|---|---|---|---|---|
| kon (M-1 s-1) | 5600 ± 756 | 1050000 ± 155957 | 333000 ± 30380 | 572000 ± 26986 | 659 ± 145.8 |
| koff (s-1) | 0.0954 ± 0.0098 | 0.00512 ± 0.0000469 | 0.405 ± 0.023 | 0.0402 ± 0.0027 | 0.164 ± 0.029 |
| t1/2a (s) | 6.90 ± 0.29 | 134.77 ± 1.25 | 1.71 ± 0.10 | 17.23 ± 0.97 | 4.21 ± 0.815 |
| KD (koff/kon) (nM) | 17250 ± 2722 | 4.94 ± 0.80 | 1220 ± 77.0 | 70.4 ± 0.591 | 259000 ± 79728 |
| Equilibrium KD (nM) | 21255 ± 7889 | 7.27 ± 1.74 | 682.2 ± 282.1 | 74.1 ± 24.5 | 304858 ± 150365 |
| ΔG (kcal mol-1) | -6.50 ± 0.09 | -11.33 ± 0.09 | -8.07 ± 0.037 | -9.76 ± 0.005 | Not tested |
| ΔH (kcal mol-1) | -7.86 ± 0.79 | -7.98 ± 0.32 | -14.46 ± 0.28 | -15.04 ± 0.63 | Not tested |
| TΔS (kcal mol-1) | -1.36 ± 0.79 | +3.35 ± 0.32 | -6.39 ± 0.28 | -5.28 ± 0.63 | Not tested |
| ΔS (cal mol-1 K-1) | -4.55 ± 2.66 | +11.25 ± 1.08 | -21.48 ± 0.83 | -17.71 ± 2.09 | Not tested |
| ΔCp (kcal mol-1 K-1) | -0.29 ± 0.17 | -1.12 ± 0.14 | -0.91 ± 0.16 | -0.60 ± 0.17 | Not tested |
a
t1/2 = 0.69/koff