Inhibition kinetics of FXa or prothrombinase
| . | Inhibitor . | |
|---|---|---|
| Antithrombin III, k2 ± SD × 103, M−1 s−1 . | TFPI, Ki*, nM . | |
| Free FXa | ||
| wt-FXa | 1.28 ± 0.060 | 0.07 ± 0.012 |
| FXaI16L | 0.03 ± 0.006 | 1.86 ± 0.340 |
| FXaV17A | 0.05 ± 0.002 | 1.16 ± 0.120 |
| Prothrombinase | ||
| wt-FXa | 0.18 ± 0.010 | ND |
| FXaI16L | 0.09 ± 0.006 | ND |
| FXaV17A | 0.05 ± 0.003 | ND |
| . | Inhibitor . | |
|---|---|---|
| Antithrombin III, k2 ± SD × 103, M−1 s−1 . | TFPI, Ki*, nM . | |
| Free FXa | ||
| wt-FXa | 1.28 ± 0.060 | 0.07 ± 0.012 |
| FXaI16L | 0.03 ± 0.006 | 1.86 ± 0.340 |
| FXaV17A | 0.05 ± 0.002 | 1.16 ± 0.120 |
| Prothrombinase | ||
| wt-FXa | 0.18 ± 0.010 | ND |
| FXaI16L | 0.09 ± 0.006 | ND |
| FXaV17A | 0.05 ± 0.003 | ND |
The errors in the fitted constants represent ± 2 SDs. The data are representative of 2-3 independent measurements. Inhibition kinetics of FXa alone or prothrombinase were determined from initial velocity studies conducted with peptidyl substrate, Spec Xa. Details of the experimental design can be found in “Methods.”
ND, not determined.