Fig. 7.

Hypothetical free energy curve of various structural forms of human telomeric G-DNA (adapted from Ref. [34]) suggested based on MM–PBSA calculations. Anti-parallel human telomeric G-DNA is more stable than the parallel counterpart. Dimerization of the parallel G-DNA structures is predicted to lead to stabilization, though, in this particular case, it is still not sufficient to make the allparallel quadruplex more stable (trimers or other types of dimers were not tested and therefore are not included). Note, however, that such challenging computations can already be significantly affected by the force field and MM–PBSA approximations (see the text).