Characterization of FIXa function
| Protein . | FXa generation . | FVIIIa binding . | ||
|---|---|---|---|---|
| Km (nM) . | kcat (s−1) . | kcat/Km (nM−1s−1) . | KD (nM) . | |
| FIXa-WT | 72.5 ± 9.8 | 1.5 ± 0.05 | 0.02068 | 2.8 ± 0.3 |
| FIXa-V17I | 243 ± 40 | 1.2 ± 0.08 | 0.0049 | 2.4 ± 0.3 |
| FIXa-V16L | 121 ± 14 | 1.0 ± 0.03 | 0.0082 | 22 ± 1.3 |
| FIXa-V16T | 330 ± 70 | 0.29 ± 0.02 | 0.0008 | 46 ± 4.8 |
| Protein . | FXa generation . | FVIIIa binding . | ||
|---|---|---|---|---|
| Km (nM) . | kcat (s−1) . | kcat/Km (nM−1s−1) . | KD (nM) . | |
| FIXa-WT | 72.5 ± 9.8 | 1.5 ± 0.05 | 0.02068 | 2.8 ± 0.3 |
| FIXa-V17I | 243 ± 40 | 1.2 ± 0.08 | 0.0049 | 2.4 ± 0.3 |
| FIXa-V16L | 121 ± 14 | 1.0 ± 0.03 | 0.0082 | 22 ± 1.3 |
| FIXa-V16T | 330 ± 70 | 0.29 ± 0.02 | 0.0008 | 46 ± 4.8 |
The apparent Km, kcat, and Kd(app) values for the activation of FX were determined from the rate of FXa generation by fitting data in Figure 1B-C as detailed in “Methods.” The data are reported as the fitted values ± 2 SD. Data are representative of 3 independent experiments.