Divalent metal ion effect on helix-coil transition of high molecular weight DNA in neutral and alkaline solutions

0361375 - ÚOCHB 2012 RIV GB eng J - Journal Article
Sorokin, V. A. - Valeev, V. A. - Usenko, E. L. - Andrushchenko, Valery
Divalent metal ion effect on helix-coil transition of high molecular weight DNA in neutral and alkaline solutions.
International Journal of Biological Macromolecules. Roč. 48, č. 2 (2011), s. 369-374. ISSN 0141-8130. E-ISSN 1879-0003
R&D Projects: GA ČR GAP208/10/0559
Institutional research plan: CEZ:AV0Z40550506
Keywords : DNA melting * alkaline solution * metal complex * differential UV spectroscopy * thermal denaturation
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.453, year: 2011

Effect of Mg2+, Ca2+, Ni2+ and Cd2+ ions on parameters of DNA helix-coil transition in sodium cacodylate (pH 6.5), Tris (pH 8.5) and sodium tetraborate (pH 9.0) buffers have been studied by differential UV-visible spectroscopy and thermal denaturation. Anomalous behavior of the melting temperature Tm and the melting interval .delta.Т in the presence of MgCl2 was observed in Tris, but not in cacodylate or tetraborate buffers. Decrease of the Tm and .delta.Т of DNA in the presence of Ni2+ and Cd2+ was caused by preferential ion interaction with N7 of guanine. This type of interaction was also found for Mg2+ in Tris buffer. The anomalous decrease in the Tm and .delta.Т values was connected to formation of complexes between metal ions and Tris molecules.
Permanent Link: http://hdl.handle.net/11104/0198698