Theoretical and experimental study of DNA helix-coil transition in acidic and alkaline medium.

The theoretical approach to the calculation of the influence of selective binding of small ligands on DNA helix-coil transition has been described in the previous paper (Lando D. Yu., J.

A theoretical consideration of the influence of selective binding of small ligands on DNA helix-coil transition.

The influence of small ligands on DNA helix-coil transition is considered theoretically. The ligands are supposed to interact with DNA base pairs reversibly and selectively. The long-range ligand-ligand interactions are taken into account.

A method for determining the relative effect of ligands on A-T and G-C base pairs in DNA: applications to metal ions, protons and two amino acids.

A new method is described for the study of specific interactions of low-molecular ligands with the base pairs of DNA. This method is based on the comparative analysis of melting temperature changes in DNAs of different GC-content in the presence of low molecular weight ligands. In this paper, the method is applied to Mn2+, Ni2+, Co2+ ions, deprotonation, amino acids, beta-alanine and gamma-aminobutyric acid (gamma-ABA).