Table 1.
Biologic Assessment of Zymogen-like FXa Variantsa
| Substrate/Inhibitor | Spec Xa | ATIII | Prothrombin | |||
|---|---|---|---|---|---|---|
|
| ||||||
|
Km μM |
kcat s−1 |
k2 ± SD × 103 M−1s−1 |
Km μM |
kcat s−1 |
t1/2
b min |
|
| Free FXa | ||||||
|
| ||||||
| wt-FXa | 86 ± 7 | 75 ± 1.5 | 1.67 ± 0.07 | -- | -- | 0.23 ± 0.01 |
|
| ||||||
| FXa-V17M | 600 ± 60 | 62 ± 3.2 | 0.1 ± 0.008 | -- | -- | 2.2 ± 0.08 |
|
| ||||||
| FXa-I16L | 1200 ± 270 | 38 ± 8.0 | 0.03 ± 0.002 | -- | -- | 8.2 ± 0.7 |
| FXa-V17T | > 1mM | <35 | 0.02 ± 0.001 | -- | -- | 16 ± 1.1 |
| FXa-I16M | > 1mM | <30 | 0.02 ± 0.0008 | -- | -- | 23 ± 2.0 |
| FXa-V17S | > 1mM | <15 | 0.01 ± 0.0007 | -- | -- | 61 ± 2.5 |
| FXa-I16T | > 1mM | <1 | ND | -- | -- | 89 ± 5.8 |
|
| ||||||
| Prothrombinase | ||||||
|
| ||||||
| wt-FXa | 160 ± 20 | 115 ± 4.0 | -- | 0.40 ± 0.04 | 45 ± 1.3 | -- |
|
| ||||||
| FXa-V17M | 260 ± 50 | 64 ± 4.9 | -- | 0.36 ± 0.04 | 38 ± 1.2 | -- |
|
| ||||||
| FXa-I16L | 370 ± 30 | 47 ± 1.9 | -- | 0.39 ± 0.03 | 42 ± 1.4 | -- |
| FXa-V17T | 540 ± 60 | 60 ± 3.8 | -- | 0.38 ± 0.05 | 33 ± 1.3 | -- |
| FXa-I16M | 500 ± 80 | 55 ± 5.1 | -- | 0.38 ± 0.05 | 42 ± 2.0 | -- |
|
| ||||||
| FXa-V17S | 1100 ± 130 | 41 ± 8.5 | -- | 0.20 ± 0.02 | 20 ± 0.5 | -- |
| FXa-I16T | 500 ± 63 | 5.3 ± 0.38 | -- | 0.12 ± 0.02 | 5.7 ± 0.2 | -- |