Table 1. Contributions of nucleoside substitutions and thermal stabilitiesa of TSL constructs.
| TSL | Substitution contribution | Tm (°C) | ΔH (kcal/mol) | ΔS (cal/mol) | ΔG37 (kcal/mol) |
|---|---|---|---|---|---|
| Unmodified | Precursor | 54.5 ± 0.3 | –49.0 ± 1.0 | –149.0 ± 4.0 | –2.6 ± 0.1 |
| T54 | Natural modification | 56.7 ± 0.4 | –52.0 ± 2.0 | –157.0 ± 7.0 | –3.1 ± 0.1 |
| T54 m5C60b | Natural modification in unnatural position | 57.2 ± 0.2 | –49.0 ± 1.0 | –149.0 ± 3.0 | –3.0 ± 0.1 |
| T54Ψ55 | Natural modifications | NDc | ND | ND | ND |
| dU54 | Sugar pucker in C2′-endo conformation | 53.2 ± 0.5 | –48.0 ± 2.0 | –146.0 ± 8.0 | –2.4 ± 0.1 |
| dU55 | Sugar pucker prefers C2′-endo | 53.7 ± 0.6 | –49.0 ± 2.0 | –151.0 ± 6.0 | –2.5 ± 0.1 |
| dU54dU55 | Sugar pucker prefers C2′-endo | 52.9 ± 0.4 | –48.0 ± 2.0 | –146.0 ± 6.0 | –2.3 ± 0.2 |
| Ψ55 | Natural modification | 53.8 ± 0.8 | –49.0 ± 5.0 | –149.0 ± 20.0 | –2.5 ± 0.3 |
| m1Ψ55d | Negates hydrogen bonding at N1 position | 53.8 ± 0.3 | –47.0 ± 1.0 | –143.0 ± 3.0 | –2.4 ± 0.1 |
| m1m3Ψ55 | Negates hydrogen bonding capabilities | 53.2 ± 0.8 | –48.0 ± 3.0 | –148.0 ± 8.0 | –2.4 ± 0.2 |
aValues are averages based on four different RNA concentrations for most oligomers. Errors are standard deviations derived from multiple iterations of denaturation and renaturation. ΔG values were calculated at 37°C.
bValues based on two different RNA concentrations.
cND, not determined.
dValues based on one RNA concentration.