The dual stabilizing and destabilizing effect of decylamine on DNA structure and stability

: The influence of decylamine on DNA structure and stability has been studied from the changes in UV-spectra and UV-melting curves. It was found that at low concentrations, the aliphatic amine stabilizes the double helix while at high concentrations, on the contrary, the amine disturbs it. The interaction of aliphatic amine with DNA results in a sharp increase in the heterogeneity of thermostability of different sites of the double helix. The stabilizing effect of aliphatic amines is connected with a decrease in repealing between negatively charged sugar-phosphate chains of the double helix, while the destabilizing effect is the result of displacement of intramolecular base-base hydrogen bonds by intermolecular base-amine H-bonds. The biological significance of the dual, stabilizing and destabilizing effects of aliphatic amines on DNA helix is shown.