Table 1.
Kinetic rate constants for FPR binding to prothrombin and its products.
| k12 (s−1) | k21 (s−1) | kon (μM−1s−1) | koff (s−1) | Kd,app (μM)a | Kd,app (μM)b | E*:E | |
|---|---|---|---|---|---|---|---|
| Prothrombin | 6.9 ± 0.3 | ≥38 ± 3 | ≥1.5 ± 0.1 | ≥45 ± 5 | ≥200 ± 20 | 190 ± 20 | ≥6:1 |
| Prethrombin-1 | 42 ± 2 | ≥96 ± 8c | ≥0.46 ± 0.05 | 42 ± 2 | ≥92 ± 8c | 92 ± 8 | ≥2:1c |
| Prethrombin-2 | 170 ± 10 | ≥100 ± 10c | ≥0.93 ± 0.08 | 27 ± 2 | ≥29 ± 2c | 29 ± 2 | ≥1:2c |
| Meizothrombin | 8.8 ± 0.5 | 3.4 ± 0.7 | 2.5 ± 0.3 | 0.8 ± 0.1 | 0.44 ± 0.03 | 0.51 ± 0.04 | 1:3 |
| Thrombin | 16 ± 1 | 3.8 ± 0.8 | 2.6 ± 0.3 | 0.6 ± 0.1 | 0.29 ± 0.02 | 0.28 ± 0.02 | 1:4 |
aCalculated from eq. 3. bDetermined by direct fluorescence titration. cCalculated under the assumption that kon = 1.5 μM−1 s−1. Experimental conditions are: 400 mM ChCl, 50 mM Tris, 0.1% PEG8000, pH 8.0, at 15 °C.