TABLE 1.
Best‐fit thermodynamic parameters for the NN model of Trp‐binding cooperativity for native MS titration data (room temperature ~ 25°C) a
| Protein | ΔG N# (kcal mol−1) | 1/K N# (μM) b | Cooperativity factor | ||
|---|---|---|---|---|---|
| ΔG 0 | ΔG 0 + ΔG α | 1/K 0 | 1/(αK 0) | α | |
| Bha TRAP12 | −4.3 ± 0.1 | −7.6 ± 0.2 | 720 ± 140 | 2.8 ± 0.8 | 256 ± 87 |
| Bst TRAP12 ∆71 | −5.00 ± 0.03 | −7.0 ± 0.1 | 217 ± 13 | 7.8 ± 1.2 | 28 ± 5 |
| Bst TRAP11 | −6.1 ± 0.2 | −7.3 ± 0.3 | 36 ± 12 | 4.4 ± 1.9 | 8 ± 5 |
Abbreviations: MS, mass spectrometry; NN, nearest‐neighbor; TRAP, trp RNA‐binding attenuation protein.
a
Thermodynamic parameters from global fitting of titration data to the nearest‐neighbor model, with free energy changes for binding to sites with 0, or 1 occupied neighbors ΔG N0, and ΔG N1 = ΔG 0 + ΔG α , respectively. Values are best fit parameters, while uncertainties are standard deviations from three datasets. Standard deviation was calculated between replicates.
b
Dissociation equilibrium constants are the reciprocal of the corresponding association equilibrium constants.