Table 3.
Global Stability of PDZ3 Domains.
| PDZ3 | [Urea]50%a (M) | ΔGD-Na (kcal mol−1) | [Urea]50%b (M) | ΔGD-Nb (kcal mol−1) | m D-N b (kcal mol−1 M−1) |
|---|---|---|---|---|---|
| H. sapiens | 6.2±0.4 | 7.6±1.3 | 6.5±0.4 | 6.3±1.3 | 1.0±0.2 |
| S. kowalevskii | 2.7±0.1 | 3.3±0.9 | 2.7±0.1 | 4.3±0.9 | 1.6±0.3 |
| D. melanogaster | 2.1±0.1 | 2.6±0.3 | 2.1±0.1 | 2.4±0.3 | 1.2±0.1 |
| D. melanogaster α3 | 3.0±0.1 | 4.0±0.4c | 3.0±0.04 | 4.4±0.3 | 1.5±0.1 |
| D. ponderosae | 3.7±0.1 | 4.5±0.8 | 3.7±0.1 | 5.1±0.8 | 1.4±0.2 |
| D. ponderosae α3 | 4.5±0.1 | 6.0±0.6c | 4.4±0.05 | 7.2±0.7 | 1.6±0.2 |
| L. loa | 4.1±0.1 | 5.0±1.4 | 4.0±0.1 | 7.0±1.4 | 1.7±0.3 |
| L. loa α3 | 5.7±0.1 | 7.7±0.7c | 5.8±0.2 | 6.6±1.4 | 1.1±0.2 |
| O. bimaculoides | 3.1±0.1 | 3.8±0.8 | 3.2±0.1 | 4.6±0.8 | 1.5±0.3 |
| H. vulgaris | 2.9±0.1 | 3.6±0.8 | 2.9±0.1 | 3.9±0.8 | 1.3±0.3 |
| Bilateria | 5.2±0.2 | 6.4±0.6 | 5.4±0.2 | 4.1±0.6 | 0.8±0.1 |
| Bilateria AltAll | 5.75±0.03 | 7.1±0.3 | 5.78±0.04 | 6.8±0.3 | 1.17±0.05 |
| Protostomia | 5.1±0.1 | 6.3±1.2 | 5.1±0.1 | 6.4±1.2 | 1.2±0.2 |
| Protostomia AltAll | 5.3±0.2 | 6.5±1.4 | 5.3±0.2 | 5.9±1.4 | 1.1±0.3 |
| Deuterostomia | 6.0±0.1 | 7.4±0.6 | 6.1±0.1 | 7.1±0.6 | 1.2±0.1 |
| Deuterostomia AltAll | 4.7±0.1 | 5.8±0.9 | 4.7±0.1 | 5.1±0.9 | 1.1±0.2 |
| Hexapoda | 7.0±0.7 | 10±4.0d | 6.7±0.4 | 17±13 | 2.5±2.0 |
| Hexapoda AltAll | 5.2±0.3 | 7.4±2.8d | 5.3±0.4 | 5.8±3.0 | 1.1±0.5 |
| 1R | 6.1±0.2 | 7.5±2.4 | 5.9±0.2 | 9.4±2.3 | 1.6±0.4 |
| 1R AltAll | e | 6.6±0.5 | 13±7.2 | 1.9±1.1 |
Note.—Global stability of PDZ3 domains was determined by urea denaturation experiments monitored by circular dichroism at 222 nm (see fig. 6). Experimental data were fitted to a two-state model for denaturation to obtain the concentration of urea, where 50% of the protein is denatured ([Urea]50%), the cooperativity of the unfolding (mD-N value) and the stability (ΔGD-N) as the product of [Urea]50%.and mD-N.
a
The mD-N value was shared among the data sets in the curve fitting; mD-N=1.23 kcal mol−1 M−1.
b
Free fitting of both [Urea]50% and mD-N.
Exceptions: cα3 PDZ3 mD-N=1.35 kcal mol−1 M−1; dHexapoda and Hexapoda AltAll mD-N=1.43 kcal mol−1 M−1; and e1R AltAll.