Table 3.
Equilibrium parameters for CD-monitored urea denaturation of NCBD variants determined in 20 mM sodium phosphate, pH 7.4, 150 mM NaCl, 1 M TMAO at 10°C.
| NCBD variant | [Urea]50%*
(M) |
△GD-N*
(kcal mol−1) |
[Urea]50%†
(M) |
mD-N†
(kcal mol−1) |
△GD-N†
(kcal mol−1) |
|---|---|---|---|---|---|
| D/P‡ | 2.4 ± 0.4 | 1.5 ± 0.3 | 2.2 ± 0.2 | 0.56 ± 0.04 | 1.2 ± 0.2 |
| D/P T2062I | 3.3 ± 0.3 | 2.0 ± 0.3 | 3.4 ± 0.1 | 0.70 ± 0.08 | 2.4 ± 0.3 |
| 1R/2R | 4.4 ± 0.3 | 2.7 ± 0.3 | 4.4 ± 0.1 | 0.67 ± 0.05 | 3.0 ± 0.3 |
| Fish/tetrapod CREBBP | 4.0 ± 0.3 | 2.5 ± 0.3 | 4.0 ± 0.1 | 0.62 ± 0.05 | 2.5 ± 0.2 |
| Hsa CREBBP | 3.8 ± 0.3 | 2.3 ± 0.3 | 3.7 ± 0.2 | 0.46 ± 0.09 | 1.7 ± 0.4 |
| Hsa p300 | 4.4 ± 0.3 | 2.7 ± 0.3 | 4.4 ± 0.3 | 0.66 ± 0.17 | 2.9 ± 0.8 |
| Dre CREBBP1§ | 3.4 ± 0.3 | 2.1 ± 0.3 | 2.2 ± 1.6 | 0.33 ± 0.16 | 0.7 ± 0.6 |
| Pma | 4.1 ± 0.2 | 2.5 ± 0.3 | 4.2 ± 0.6 | 0.50 ± 0.22 | 2.1 ± 1.0 |
| Dmel | 1.6 ± 0.5 | 1.0 ± 0.3 | 2.6 ± 0.4 | 1.2 ± 0.7 | 3.3 ± 1.9 |
*The mD-N value was shared among the datasets in the curve fitting; mD-N = 0.61 ± 0.05 kcal mol−1M−1.
†Free fitting of both [Urea]50% and mD-N.
‡D/P, Deuterostome/protostome node; 1R/2R, the node(s) around the time of the two whole genome duplications in the vertebrate lineage; Fish/tetrapod, the node where fish diverged from tetrapods; Hsa, Homo sapiens; Dre, Danio rerio (zebrafish); Pme, Petromyzon marinus, (sea lamprey); Dmel, Drosophila melanogaster (fruit fly).
§The bony fish lineage experienced a third whole-genome duplication and has two variants of CREBBP NCBD.