title: Effect of Ni2+ and Cd2+ ions on thermally induced conformational transitions in poly(dA)-poly(dT) system.
abstract: Effects of Ni(2+) and Cd(2+) ions on thermally induced conformational transitions in the poly(dA)·poly(dT) polynucleotide duplex and poly(dA)·2poly(dT) triplex under near physiological ionic conditions were studied by measurement of UV absorption melting curves and static light scattering intensity. The diagrams of conformational transitions in poly(dA)-poly(dT)-Me(2+) systems were plotted. An aggregation in these polynucleotide systems arises at certain values of the metal ions concentration and the temperature after the polymer dissociation into single strands. The phenomenon is conditioned by the aggregation of poly(dA) via the interstrand cross-linking by the dication bridges. Unlike Ni(2+), Cd(2+) induces formation of very stable aggregates which did not disintegrate even upon cooling up to room temperature.
authors.affiliation: Department of Molecular Biophysics, B.Verkin Institute for Low Temperature Physics & Engineering of NAS of Ukraine, 47 Lenin ave, 61103, Kharkov, Ukraine. zozulya@ilt.kharkov.ua
authors.forename: Victor N
authors.initials: VN
authors.lastname: Zozulya
authors.forename: Olga A
authors.initials: OA
authors.lastname: Ryazanova
authors.forename: Nataliya N
authors.initials: NN
authors.lastname: Zhigalova
authors.forename: Yurii P
authors.initials: YP
authors.lastname: Blagoi
mesh_terms: D019256:Cadmium Chloride / Q000494:pharmacology*; D002413:Cations, Divalent / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology*; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D011067:Poly dA-dT / Q000737:chemistry*; D011089:Polydeoxyribonucleotides / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002413:Cations, Divalent; D011089:Polydeoxyribonucleotides; C098037:poly(dA)(poly(dT))2; D011067:Poly dA-dT; C022838:nickel chloride; D009532:Nickel; D019256:Cadmium Chloride