Table 1. Cleavage and religation rate constants of CPT and TFO in the 27 and 30mer (I) oligonucleotides.
| 27mer | 30mer (I) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0°C | 25°C | 25°C | 0°C | |||||||||
| CPT | TFO | Ratio TFO/CPT | CPT | TFO | Ratio TFO/CPT | CPT | TFO | Ratio TFO/CPT | CPT | TFO | Ratio TFO/CPT | |
| T1/2 (min) | 4.5 | 76 | 16.88 | 0.15 | 3.9 | 26 | 0.36 | <0.09 | <0.25 | 7.6 | <0.4 | <0.05 |
| k2 (min−1) | 0.15 | 0.009 | 0.06 | 4.62 | 0.18 | 0.04 | 1.93 | >7.7 | >4 | 0.087 | >1.8 | >20.69 |
| k1 (min−1) | NA | NA | NA | 0.68 | 0.04 | 0.06 | 2.45 | >2.99 | >1.22 | 0.224 | >1.41 | >6.3 |
| r | NA | NA | NA | 0.13 | 0.19 | 1.46 | 0.56 | 0.28 | 0.5 | 0.72 | 0.44 | 0.61 |
T1/2, Religation rate half-life determined from the salt reversal experiments (see Figures 3B, 3C, 4D, 4E, 5E and 6E); k2, religation rate constant determined from T1/2; k1, cleavage rate constant (see Materials and Methods); r, the fraction of cleavage product at steady state (see Figures 2C, 4C, 5D and 6D); NA, not applicable as the Top1-mediated DNA cleavage failed to form measurably in the presence of TFO at 0°C.