Range of enzyme kinetic parameters of FX activation by FIXa and cofactors
| Cofactor . | KM (nM) . | kcat (s−1) . | kcat/KM (nM−1 s−1) . | Fold (no cofactor) . |
|---|---|---|---|---|
| None | 60-400 | 0.1 × 10−4 to 2 × 10−4 | 0.1 × 10−6 to 2 × 10−6 | 1 |
| A2 | 100 | 2 × 10−2 | 2 × 10−4 | 1 × 102 |
| A2 + A1 | 100 | 2 × 10−1 | 2 × 10−3 | 1 × 103 |
| FVIIIa | 30-40 | 1-3 | 1 × 10−1 | 5 × 104 to 100 × 104 |
| Emicizumab | 3-8 | 0.2 × 10−2 to 5 × 10−2 | 7 × 10−3 to 10 × 10−3 | 2 × 104 |
| Cofactor . | KM (nM) . | kcat (s−1) . | kcat/KM (nM−1 s−1) . | Fold (no cofactor) . |
|---|---|---|---|---|
| None | 60-400 | 0.1 × 10−4 to 2 × 10−4 | 0.1 × 10−6 to 2 × 10−6 | 1 |
| A2 | 100 | 2 × 10−2 | 2 × 10−4 | 1 × 102 |
| A2 + A1 | 100 | 2 × 10−1 | 2 × 10−3 | 1 × 103 |
| FVIIIa | 30-40 | 1-3 | 1 × 10−1 | 5 × 104 to 100 × 104 |
| Emicizumab | 3-8 | 0.2 × 10−2 to 5 × 10−2 | 7 × 10−3 to 10 × 10−3 | 2 × 104 |
Tabulated ranges are based on previous published studies.53-58