Iermak I. The competitive binding of the biologically active substances to nucleic acids

The thesis is dedicated to experimental study of physical mechanisms of interactions of biologically active ligands with nucleic acids in the case of multimodal binding of one of the ligands. Оptimal models of binding and thermodynamic and stochiometric parameters of binding of ligands to studied polymeric matrixes are obtained. It is shown that theophylline, caffeine, cytidine and its analogues form one type of complexes with DNA and also not intercalate into DNA. It is also shown that these substances decrease the amount of competing ligand that aggregated on DNA. The study the competitive binding of several biologically active compounds that both absorb in the same wavelengths region was carried out on the system ActII -DNA - ethidium bromide and ActII -DNA - Hoechst 33258. It is shown that ethidium bromide decreases the amount of intercalated into DNA ActII and Hoechst 33258 decreases the amount of monomerically bounded ActII.