Probing the role of dispersion energy on structural transformation of double-stranded xylo- and ribo-nucleic acids†
The structural transformation of double-stranded octameric xyloNA and RNA were probed by modulating the dispersion energy. For the RNA, the increase and the decrease in dispersion energy lead to over-winding and unwinding of the helix. These structural transformations resemble the features observed due to the action of the topoisomerases and helicases enzymes, respectively. On the other hand, an increase in the dispersion energy has minimal effect on the structural transformation of double-strand xyloNA, whilst a decrease in the dispersion energy results in a structural transformation which happens due to the action of the helicases. The unresponsive behaviour of xyloNA to an increase in the dispersion energy is attributed to the presence of an Lp⋯π interaction between the oxygen atom of the xylose sugar and the adjacent nucleobase.