Table 2.
2′F-RNA- and 2′F-ANA-modified sequences used in this study and their thermal stability
| Namea | Sequence (5′→3′)b | Tm(°C)c | ΔTm(°C) |
|---|---|---|---|
| (4+0) native | TTGGGTGGGTGGGTGGGT | 76.5 ± 0.4 | |
| PS-F-3 | TTFGGTGGGTGGGTGGGT | 76.8 ± 0.1 | 0.3 |
| PS-F-4 | TTGFGTGGGTGGGTGGGT | 77.0 ± 0.0 | 0.5 |
| PS-F-5 | TTGGFTGGGTGGGTGGGT | 75.4 ± 0.1 | −1.1 |
| PS-F-8 | TTGGGTGFGTGGGTGGGT | 76.9 ± 0.1 | 0.3 |
| PS-F-11 | TTGGGTGGGTFGGTGGGT | 77.2 ± 0.2 | 0.7 |
| PS-F-12 | TTGGGTGGGTGFGTGGGT | 75.4 ± 0.1 | −1.1 |
| PS-F-13 | TTGGGTGGGTGGFTGGGT | 76.6 ± 0.3 | 0.1 |
| PS-F-17 | TTGGGTGGGTGGGTGGFT | 75.2 ± 0.0 | −1.4 |
| PS-FANA-3 | TTFGGTGGGTGGGTGGGT | 77.1 ± 0.2 | 0.6 |
| PS-FANA-4 | TTGFGTGGGTGGGTGGGT | 79.7 ± 0.0 | 3.2 |
| PS-FANA-5 | TTGGFTGGGTGGGTGGGT | 77.2 ± 0.3 | 0.6 |
| PS-FANA-8 | TTGGGTGFGTGGGTGGGT | 79.7 ± 0.0 | 3.2 |
| PS-FANA-11 | TTGGGTGGGTFGGTGGGT | 77.2 ± 0.2 | 0.6 |
| PS-FANA-12 | TTGGGTGGGTGFGTGGGT | 79.3 ± 0.0 | 2.7 |
| PS-FANA-13 | TTGGGTGGGTGGFTGGGT | 76.6 ± 0.3 | 0.1 |
| PS-FANA-17 | TTGGGTGGGTGGGTGGFT | 76.3 ± 0.2 | −0.2 |
| (3+1) native | TTGGGTTAGGGTTAGGGTTAGGGA | 51.4 ± 0.2 | |
| HT-F-3 | TTFGGTTAGGGTTAGGGTTAGGGA | ||
| HT-F-4 | TTGFGTTAGGGTTAGGGTTAGGGA | 51.6 ± 0.4 | 0.2 |
| HT-F-5 | TTGGFTTAGGGTTAGGGTTAGGGA | 51.2 ± 0.3 | −0.2 |
| HT-F-9 | TTGGGTTAFGGTTAGGGTTAGGGA | ||
| HT-F-10 | TTGGGTTAGFGTTAGGGTTAGGGA | 48.9 ± 1.2 | −2.5 |
| HT-F-11 | TTGGGTTAGGFTTAGGGTTAGGGA | 49.8 ± 0.8 | −1.6 |
| HT-F-15 | TTGGGTTAGGGTTAFGGTTAGGGA | ||
| HT-F-16 | TTGGGTTAGGGTTAGFGTTAGGGA | ||
| HT-F-17 | TTGGGTTAGGGTTAGGFTTAGGGA | 48.7 ± 0.5 | −2.7 |
| HT-F-21 | TTGGGTTAGGGTTAGGGTTAFGGA | ||
| HT-F-22 | TTGGGTTAGGGTTAGGGTTAGFGA | 49.8 ± 0.8 | −1.6 |
| HT-F-23 | TTGGGTTAGGGTTAGGGTTAGGFA | 49.5 ± 0.1 | −1.8 |
| HT-FANA-3 | TTFGGTTAGGGTTAGGGTTAGGGA | ||
| HT-FANA-4 | TTGFGTTAGGGTTAGGGTTAGGGA | 54.5 ± 0.3 | 3.1 |
| HT-FANA-5 | TTGGFTTAGGGTTAGGGTTAGGGA | 51.9 ± 0.6 | 0.5 |
| HT-FANA-9 | TTGGGTTAFGGTTAGGGTTAGGGA | ||
| HT-FANA-10 | TTGGGTTAGFGTTAGGGTTAGGGA | 54.5 ± 0.7 | 3.2 |
| HT-FANA-11 | TTGGGTTAGGFTTAGGGTTAGGGA | 52.9 ± 0.5 | 1.5 |
| HT-FANA-15 | TTGGGTTAGGGTTAFGGTTAGGGA | ||
| HT-FANA-16 | TTGGGTTAGGGTTAGFGTTAGGGA | ||
| HT-FANA-17 | TTGGGTTAGGGTTAGGFTTAGGGA | 53.8 ± 0.0 | 2.4 |
| HT-FANA-21 | TTGGGTTAGGGTTAGGGTTAFGGA | ||
| HT-FANA-22 | TTGGGTTAGGGTTAGGGTTAGFGA | 53.5 ± 0.7 | 2.2 |
| HT-FANA-23 | TTGGGTTAGGGTTAGGGTTAGGFA | 51.9 ± 0.5 | 0.6 |
aThe ‘HT-series’ denotes sequences modified from the (3+1) G-quadruplex-forming sequence, while the ‘PS-series’ denotes sequences modified from a (4+0) G-quadruplex-forming sequence.
bResidues with modified nucleotides are denoted as such: 2′F-RNA-guanosine (F) and 2′F-ANA-guanosine (F).
cThermal stability data were obtained via UV melting experiments. Salt conditions were (5 mM KCl and 5 mM KPi) for the HT-series and (1 mM KPi) for the PS-series. Data for the HT-series are presented only for sequences that demonstrate a single major conformation in NMR spectra. The uncertainties (±values) indicate the hysteresis between heating and cooling curves. Information regarding thermodynamic parameters ΔH, ΔS and ΔG are presented in Supplementary Table S2.