Table 1. Comparisons of the kinetic time constants (τ) and the absorption coefficients (ε) at the isosbestic points for wildtype and Q513 mutants in the dark state.
The kinetics experiments are recorded at room temperature (22°C) for 200 s and the data points were fitted using a first order exponential rate equation to obtain the time constant (τ). The dark recovery time constant at A446 is measured by UV-visible absorbance spectroscopy while the dark recovery time constant at θ222 is measured via CD spectroscopy.
| Construct | τdark recovery[A446] (s) | τdark recovery[θ222] (s) | ε446 (M-1 cm-1) | Isosbestic points (nm) |
|---|---|---|---|---|
| WT | 68.3 | 72.4 | 11700 | 327, 388, and 406 |
| Q513N | 37.3 | 40.6 | 12400 | 330, 388, and 406 |
| Q513L | 1080 | >1000 | 10700 | 330, 380, and 403 |