Table 1.
Helical Parameters of PNA and Modified DNA Duplexes
| Duplex | Helical sense | Disp. (Å) | Rise* (Å) | Inclination (°) | Tilt (°) | Twist * (°) | Slide (°) | Roll (°) | BP/turn | Ref | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| H-GGCATGCC-Lys-NH2[b] | X-ray | R | −8.2 | 3.3 | 1.0 | −0.3 | 18.8 | −0.3 | −0.2 | 19 | this paper |
| L | 8.4 | 3.2 | 1.8 | 0.3 | −18.8 | −0.2 | 0.4 | 19 | |||
| H-GGCATGCC-Lys-NH2[b] | NMR | L | 7.9 | 3.7 | −5.0 | −0.2 | −17.3 | −0.22 | −0.60 | 21 | [46] |
| H-CGTACG-NH2 | X-ray | R | 8.3 | 3.2 | 0.3 | 1.0 | 19.8 | 0.06 | 1.81 | 18 | [4] |
| H-CGTACG-L-Lys-NH2 | X-ray | L | 6.6 | 3.4 | −5.02 | 0 | −19 | −0.74 | −5.12 | 18 | [5] |
| R | 7.7 | 3.2 | −5.47 | 0 | 20.5 | −0.41 | 5.17 | 18 | |||
| H-GTAGATCACT-L-Lys-NH2 | X-ray | L | 7.9 | 3.3 | −8.9 | 0 | −18 | / | / | 20 | [6] |
| R | 3.5 | 3.4 | −26.7 | 0 | 19.1 | / | / | 19 | |||
| 3′-CGHATHCG-2′[c] | X-ray | R | −7.0 | 3.8 | / | 0 | 22.9 | −3.4 | −2.8 | 16 | [47] |
| 4′-dd(CGAATTCG)-6′[d] | R | / | 3.8 | / | 1.9 | 14.3 | 4.4 | 4.9 | 25 | [48] | |
| 5′-h(GTGTACAC)-3′[e] | Hex, R | −6.2 | 2.2 | 24.3 | / | 33.2 | −2.5 | 11.5 | 11 | [49] | |
| Trig, R | −6.5 | 3.3 | 3.4 | / | 24.2 | −3.3 | 4.1 | 15 |
[b]
Helical parameters calculated using Curves and assuming a linear helical axis.
[c]
(S)-glycol nucleic acid with an acyclic, three-carbon propylene glycol phosphodiester backbone. H represents hydroxypyridone ligand instead of a nucleobase.
[d]
Homo-DNA with 2′,3′-dideoxy-β-D-glucopyranose sugar-phosphodiester backbone.
[e]
Hexitol nucleic acid with an extra methylene group between C1′ and O4′ of the backbone β-D-2′-deoxyribose.