Khrebtova A. Influence of ligands on thermodynamical characteristics of helix – coil transition in polynucleotides

Object of investigation: the thermal denaturation of the biologically active ligands to a polynucleotide matrix. Aim of work: to study the effect of aromatic ligands on the parameters of the helix – coil transition of nucleic acids(NA) for a complete thermodynamic description of systems NA - ligand and determine the specificity of the interaction. Methods of investigation: differential scanning calorimetry, spectrophotometric titration in the visible and ultraviolet regions of the spectrum. Scientific novelty: with the help of DSC the heat absorption curves of DNA complexes with ligands FMN, Pf, Act II and Act III, as well as semiprotonated polyribocytidylic acid poly (rC)•poly (rC+) in the presence of Act III were obtained for the first time. A new theoretical model for the analysis of DSC curves of polynucleotides in mixtures with ligand was developed. Practical application: use in molecular biophysics, molecular biology and biotechnology.