[Interaction of divalent copper ions with native DNA and its monomers].

The complex formation of Cu2+ ions with the 2'-deoxynucleotide-5'-phosphates of bases in water solution by the UV-spectroscopy method has been established. It was obtained that the N7-atom in dGMP and N3-atom in dTMP are coordinated with copper (Cu) in complexes. The deoxyribonucleotide C can not subtract with the copper (Cu). The constants (K) of Cu-bases binding have been obtained. The K-value for purines is greater than for pyrimidines independent of the ribose structure. The ions Cu2+ at formation of complexes with separate nucleotides or natural DNA can cause the conformational transitions in these molecules. Thus the ions Cu2+ interact as with N7 and O6 G, as with N3 and O2 C. It is agreed with model, in which guanosine passes from anti to sin-conformation. The interactions of Cu-ions with G, C and A base pairs in single stranded DNA have been registered.