Table 1.
Mass characterization, melting temperatures, and photomodulation efficiencies for conjugates C1–C6, showing decrease in thermal stability and increase in RNase H activity upon photoirradiation
| Photoactive conjugate | Mass (calc) | Mass (expt) | Tma (°C) | Tma (°C) (cleaved) | ΔTm (°C) | Photomodulation efficiencyb |
|---|---|---|---|---|---|---|
| C1 | 12838.2 | 12862.5 | 74 | 51 | −23 | 1.5 |
| C2 | 12807.1 | 12803.4 | 81 | 63 | −18 | 3.5 |
| C3 | 12829.4 | 12858.6 | 68 | 47 | −21 | 1.2 |
| C4 | 12789.4 | 12770.0 | 79 | 62 | −17 | 3.4 |
| C5 | 12838.4 | 12838.1 | 80 | 51 | −29 | 4.4 |
| C6 | 12807.4 | 12819.2 | 84 | 63 | –21 | 6.0 |
aMelting temperatures were determined from the peak of the first derivative plot of Abs260 versus temperature in standard RNase H buffer.
bPhotomodulation efficiency is the n-fold increase in RNA-40 cleavage elicited by photoactivation, observed in 1 h RNase H assay with 1 U enzyme.