TABLE 1.
Results from non-linear regression analysis of the calorimetric data at 10 °C
A model based on one set of independent, thermodynamically equal binding sites was fitted to the experimental data to get maximum likelihood parameters for the binding enthalpy (ΔH), stoichiometry (n), and binding constant (KB). Binding to the E212Q variant was measured for cello oligosaccharides with a DP from 2 to 8. The interaction of cellobiose (DP = 2) and the wild type TrCel7A enzyme (WT) was also measured. Errors are S.D. for 2–4 separate measurements.
| DP | Enzyme | ΔH | n | KB |
|---|---|---|---|---|
| kJ/mol | m−1 | |||
| 2 | WT | 35.8 ± 0.3 | 1.39 ± 0.04 | (1.3 ± 0.08) × 105 |
| 2 | E212Q | 30.5 ± 0.3 | 1.41 ± 0.04 | (1.8 ± 0.04) × 105 |
| 3 | E212Q | 47.3 ± 1.8 | 1.55 ± 0.13 | (7.2 ± 0.6) × 104 |
| 4 | E212Q | 33.0 ± 1.2 | 2,01 ± 0.03 | (8.7 ± 1.3) × 104 |
| 5 | E212Q | 34.1 ± 4.2 | 1.02 ± 0.11 | (1.4 ± 0.7) × 107 |
| 6 | E212Q | 35.2 ± 1.7 | 0.89 ± 0.19 | (3.6 ± 2.2) × 107 |
| 7 | E212Q | 33.9 ± 2.6 | 0.79 ± 0.12 | (2.6 ± 1.4) × 107 |
| 8 | E212Q | 36.1 ± 2.4 | 0.97 ± 0.14 | (5.3 ± 1.1) × 106 |