Table 1 Quantitative information regarding the structure and the Φdc → Φoc transitions of duplex, Poly(AT*T)-triplex, and GMP-quadruplex DNA.

From: X-ray characterization of mesophases of human telomeric G-quadruplexes and other DNA analogues

 

a (nm)

λ (e/nm)

σ (e/nm2)

P(nm)

Change in d int

Δ d int (nm)

Δ Acell(nm2)

Δ Vpn(nm3)

Duplex

1

6

0.95

3.4

≈3.7-to-3.5 nm

0.19–0.21

0.11–0.12

0.19–0.20

Poly(AT*T)-triplex

1.04

9

1.38

3.4

≈3.7-to-3.3 nm

0.35–0.40

0.19–0.22

0.22–0.24

GMP-quadruplex

1.25

12

1.53

4.1

≈4.2-to-3.5 nm

0.65–0.70

0.43–0.46

0.36–0.39

  1. The structural parameters, radius (a) and helical pitch length (P), are from refs 13,26 and 32.
  2. The distances dint are measured in 0.3 M K+ solutions for duplex and GMP-quadruplex. These distances for duplex and GMP-quadruplex decrease without a significant change in Δdint with increasing K+ concentration. The Poly(AT*T)-triplex measurements are carried out in the presence of 0.3 M K+ and 5 mM Mg2+. Lowering Mg2+ concentration any further (less than 5 mM), while keeping the K+ concentration fixed at 0.3 M, results in the disassociation of the triplexes (see SI Appendix).
  3. Acell is the hexagonal cross-sectional area surrounding the duplex, triplex, or GMP-quadruplex. ΔAcell is the change in the Wigner-Seitz cell area at the transition.
  4. ΔVpn is the change in the volume per nucleotide at the transition. The change in the volume per stacking unit (i.e., base-pair for duplex, base-triplet for triplex, and G-quartet for GMP-quadruplex) is equal to ΔAcell multiplied by the base-stacking height (see SI Appendix). The overall uncertainty in the determination of ΔVpn is about 10%.
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