Copper(II)--nucleic acid interactions--a conformational study

The effect of copper complexation upon the conformational angles in mononucleotides and dinucleotides was studied using classical potential energy expressions. The geometrical parameters were taken from crystallographic reports on the base-metal complexes. It was found that the preferred conformations of the complexes were quite different from the preferred conformations of the corresponding pure nucleotides. Notable among the disallowed conformations in case of Cu(II)-dinucleotide complexes were the regions corresponding to RRNA's, RNA's and the A, B and C forms of DNA. It is proposed that the energetics of a single strand is more important than inter-strand interactions in promoting copper-induced denaturation of DNA.