Table 2.
Thermodynamic parameters of unfolding of VHH antibody fragments at pH 7, 25°C, as obtained from the analysis of the equilibrium transitions
| VHH fragments | ΔG(H2O) (kJ mol−1) | m (kJ mol−1 M−1) | Cm (M) |
| cAb-Lys3 | |||
| GdmCla | 31 ± 5 | 13.5 ± 2 | 2.3 ± 0.5 |
| Urea | 36 ± 4 | 5.3 ± 0.6 | 6.7 ± 1 |
| cAb-HuL6 | |||
| GdmCl | |||
| Fluorescence | 40 ± 3 | 12.7 ± 1 | 3.1 ± 0.3 |
| CD (209 nm) | 43 ± 6 | 14.5 ± 2 | 3 ± 0.5 |
| CD (229 nm) | 37 ± 4 | 12 ± 1.5 | 3 ± 0.6 |
| Ureaa | (—) | (—) | >9 |
| cAb-NmcA2 | |||
| GdmCla | 34 ± 5 | 11 ± 1.5 | 3.0 ± 0.6 |
| Ureaa | (—) | (—) | ∼8 |
| cAb-BCII 10 | |||
| GdmCla | 47 ± 2 | 14.2 ± 0.7 | 3.3 ± 0.2 |
| Ureaa | 49 ± 6 | 6.6 ± 0.8 | 7.5 ± 1 |
| cAb-TEM2 | |||
| GdmCla | 55 ± 3 | 17.6 ± 0.7 | 3.1 ± 0.2 |
| Ureaa | 61 ± 7 | 8.3 ± 1 | 7.5 ± 1 |
| cAb-R2 | |||
| GdmCl | |||
| Fluorescence | 36 ± 5 | 16 ± 2.5 | 2.3 ± 0.5 |
| CD (212 nm) | 30 ± 5 | 13 ± 2.5 | 2.3 ± 0.6 |
| CD (222 nm) | 33 ± 10 | 14 ± 5 | 2.3 ± 1 |
| CD (268 nm) | 42 ± 10 | 18 ± 4 | 2.3 ± 0.7 |
| Ureaa | 38 ± 3 | 6.5 ± 0.5 | 5.8 ± 0.4 |
a Fluorescence measurements. Errors are calculated at the 95% confidence limit.
— = not accessible.