TABLE 1.
Comparison of the binding parameters and kinetic constants between POR A and POR B
The dissociation constants, KD, are derived from MST measurements and the values of the kinetic parameters are obtained from plots of the initial rates, v0, against the PChlide concentration by using a nonlinear regression analysis for the Michaelis-Menten Equation 1. The estimates are the average of four independent experiments.
| Parameter | POR A (ternary complex) | POR B (ternary complex) |
|---|---|---|
| KD (μm) | 1.0 ± 0.014 | 0.19 ± 0.009 |
| Km (μm) | 3.44 ± 0.3 | 1.25 ± 0.07 |
| Vmax (μm s−1) | 0.05 ± 0.005 | 0.1 ± 0.015 |
| kcat (s−1) | 5.5 × 10−3 ± 5.5 × 10−4 | 1.16 × 10−2 ± 1.5 × 10−3 |
| kcat/Km (s−1 m−1) | 1.6 × 103 ± 1.6 × 102 | 9.3 × 103 ± 9.3 × 102 |