title: [Effect of Mn2+ and Mg2+ ions on DNA conformation].
abstract: The DNA conformation was studied at different relation between Na+ and Me2+ (Mn2+ or Mg2+) ions in solution at the fixed total ionic strength mu. At low mu the intrinsic viscosity of DNA [eta] decreased to the limited fixed value with the increasing of Mn2+ or Mg2+ concentration (CMe2+). At higher mu greater than or equal to 0.1 M [eta] doesn't depend on CMe2+. The presence of Mn2+ in solution caused a decrease of the optical anisotropy of DNA and the value of epsilon 260 (p) independent on ionic strengths. In contrary, these parameters of DNA didn't change in solution with Mg2+-concentration. The observed differences in the effects of Mn2+ and Mg2+ on the optical properties of the macromolecule suggest that there are different modes of binding of these ions to DNA. It has been concluded, that Mn2+ interacts with bases and phosphate groups of DNA, but Mg2+--only with phosphates. The persistence length of DNA doesn't depend on Me2+ concentration under the conditions of the experiment (mu greater than or equal to 0.005 M).
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA / Q000187:drug effects*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008345:Manganese / Q000494:pharmacology*; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D012996:Solutions; D014783:Viscosity
chemical_list: D012996:Solutions; D008345:Manganese; D004247:DNA; D008274:Magnesium
vernacular_title: Issledovanie vliianiia ionov Mn2+ i Mg2+ na konformatsiiu molekuly DNK.