Table II.
Thermodynamics Parameters Obtained from Calorimetric Titration of Streptavidin (Determined at 300 K)
| Wild-type SA | −ΔH (kcal−1 mol−1) | −ΔG (kcal−1 mol−1) | −TΔS (kcal−1 mol−1) |
|---|---|---|---|
| Biotin | 29.4 ± 0.2 | 18.0 ± 0.1 | 11.4 ± 0.2 |
| Desthiobiotin | 21.7 ± 0.1 | 12.4 ± 0.2 | 9.3 ± 0.2 |
| R4–6 SA | |||
| Biotin | 20.4 ± 0.3 | ND* | ND* |
| Desthiobiotin | 22.8 ± 0.2 | 12 ± 0.1 | 10.8 ± 0.2 |
| R7–2 SA | |||
| Biotin | 21.75 ± 0.3 | 13.40 ± 0.03 | 8.3 ± 0.3 |
| Desthiobiotin | 24.2 ± 0.3 | 12.7 ± 0.1 | 11.6 ± 0.3 |
*
−ΔG and −TΔS values not calculated, since Kd values for R4–6 biotin were not determined.