Kalorimetricheskoe issledovanie vliianiia ionov Ca2+ i Mn2+ na perekhodspiral'-klubok v DNK

Using the method of differential scanning calorimetry, the DNA helix-coil transition studied in solutions containing divalent metal ions (Mn2+ and Ca2+) at relative metal ion concentrations (Me/PDNA) ranging from 0.2 to 20. Dependences of the melting temperature and enthalpy on the ion relative concentration were measured. The fine structure of melting curves in DNA+Me complexes was observed. The resolution degree of this structure was shown to increase in the range of moderate ion concentrations. The data obtained were compared with values determined by UV-spectroscopy. Association constants were defined for Mn2+ and Ca2+ binding to DNA by the ligand theory