Table 4. Effects of RNA aptamers on kinetic parameters for cleavage of S-2366 by FXIa variants.
Analysis of the aptamer dependences was performed using Km and kcat values determined independently by simplex fitting in the absence of aptamer, and fixing the best fits in nonlinear least squares analysis of Ki, α and β. Apparent Km and kcat values in the presence of aptamer were obtained by multiplying these fixed Km and kcat values by the fitted α and β, respectively.
| No Aptamer | Sel-3 Control | 11.16 | 12.7 | |
|---|---|---|---|---|
| FXIa-ABS1 | ||||
| Km (μM)* | 311 | - | 430 ± 120 | 500 ± 300 |
| kcat (s-1)* | 36 | - | 7 ± 1 | 9 ± 3 |
| Ki (μM) | - | - | 0.08 ± 0.01 | 0.28 ± 0.07 |
| α (Km factor) | 1 | - | 1.4 ± 0.4 | 1.6 ± 0.9 |
| β (kcat factor) | 1 | - | 0.19 ± 0.03 | 0.26 ± 0.07 |
| FXIa-ABS2 | ||||
| Km (μM)* | 285 | - | 510 ± 20 | - |
| kcat (s-1)* | 35 | - | 12 ± 2 | - |
| Ki (μM) | - | - | 0.25 ± 0.04 | - |
| α (Km factor) | 1 | - | 1.8 ± 0.6 | - |
| β (kcat factor) | 1 | - | 0.33 ± 0.06 | - |
| FXIa- Aut Loop | - | |||
| Km (μM)* | 290 | - | - | 460 ± 60 |
| kcat (s-1)* | 36 | - | - | 26 ± 18 |
| Ki (μM) | - | - | - | 0.28 ± 0.08 |
| α (Km factor) | 1 | - | - | 1.6 ± 0.2 |
| β (kcat factor) | 1 | - | - | 0.72 ± 0.05 |