Table 2. Measured thermodynamic parameters for short oligoribonucleotide duplexes with and without dangling adenines.
| Complementary sequence | Na+ conc.(mM) | Tm(°C) (9 × 10−6 M RNA) | −ΔHapp (kcal/mol) | −ΔSapp (cal/mol) | −ΔG37app (kcal/mol) | −ΔΔG37 (kcal/mol) |
|---|---|---|---|---|---|---|
| ACCUGCCAAGGACGGA | 1000 | 61.6 ± 0.3 | 68.1 ± 0.3 | 177.6 ± 0.1 | 13.03 | 1.69 |
| ACCGACCAAGGCUGGA | 1000 | 58.6 ± 0.3 | 70.5 ± 0.9 | 186.6 ± 0.4 | 12.62 | 0.86 |
| AGAGAGGAACUCUCCA | 1000 | 53.5 ± 0.3 | 62.3 ± 1.6 | 165.0 ± 0.7 | 11.16 | 1.12 |
| ACUAAACAAGAUUUGA | 1000 | 26.9 ± 0.1 | 49.6 ± 0.4 | 139.5 ± 0.2 | 6.34 | 1.11 |
| CCUGCCGGACGG | 1000 | 48.4 ± 0.3 | 63.90 ± 1.2 | 172.93 ± 0.5 | 10.27 | 4.45 |
| CCGACCGGCUGG | 1000 | 43.3 ± 0.4 | 59.2 ± 0.5 | 161.1 ± 0.2 | 9.21 | 4.27 |
| GAGAGGCUCUCC | 1000 | 40.0 ± 0.4 | 58.30 ± 2.3 | 160.56 ± 1.1 | 8.50 | 3.78 |
| CUAAACGAUUUG | 1000 | nc | — | — | — | — |
The differences in free energy between the measured kissing loops and short duplexes are indicated in the right column in bold; nc indicates that this sequence does not form a complex at temperatures that can be monitored.