Table 2.
Kinetic parameters and Incorporation efficiencies of GTP and AT analogues
| NTP | k max (s−1) | K d (μM) | Efficiency (E) kmax/Kd (s−1 μM−1) | Fold-reduction in efficiency | Discrimination (competition) |
|---|---|---|---|---|---|
| GTPfast | 142.3 ± 6.9 | 39.1 ± 3.7 | 3.64 ± 0.39 | 1 | 1 |
| GTPslow | 3.6 ± 0.3 | 12.9 ± 2.7 | 0.28 ± 0.06 | 13.0 | - |
| AT-9010 | 7.5 ± 0.5 | 82.4 ± 12 | 0.09 ± 0.01 | 39.9 | 7.3 ± 2.1 |
| AT-9052-SP | 2.6 ± 0.5 | 119.2 ± 45.6 | 0.02 ± 0.01 | 166.8 | 57.4 ± 16.88 |
Kinetic values (kmax and Kd) calculated from pre-steady state kinetic data (Figure 4), where efficiency (E) is kmax/Kd and fold-reduction in efficiency is calculated relative to GTPfast. Discrimination measured from multiple incorporation experiments, where each analogue is competing with GTP for insertion (Figure 5). The discrimination value represents the number of templating cytosines that would theoretically be required for the analogue to be inserted in the place of GTP, when at equimolar concentrations.