title: [Calorimetric study of Ca2+ and Mn2+ ions' effect on DNA helix-coil transition].
abstract: Using the method of differential scanning calorimetry, the DNA helix-coil transition studied in solutions (10(-3) M Na+, 10(-3) M tris HCl, pH 7.0) 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 stated. 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.
authors.forename: S V
authors.initials: SV
authors.lastname: Kornilova
authors.forename: P
authors.initials: P
authors.lastname: Iasem
authors.forename: D N
authors.initials: DN
authors.lastname: Grigor'ev
authors.forename: L E
authors.initials: LE
authors.lastname: Kapinos
authors.forename: Ia
authors.initials: Ia
authors.lastname: Totova
authors.forename: Iu P
authors.initials: IuP
authors.lastname: Blagoĭ
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry*; D002151:Calorimetry; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D013816:Thermodynamics
chemical_list: D004247:DNA; D008274:Magnesium; D002118:Calcium