@article{Blagoi_Zozulya_Egupov_Onyshchenko_2005, title={Thermodynamic analysis of conformational transitions in double- and three-stranded helices formed by poly dA and poly dT molecules in solutions with Na+ and Mg2+ ions, using the "staggering zipper" model}, volume={1}, url={https://periodicals.karazin.ua/biophysvisnyk/article/view/17999}, abstractNote={<p>The present work considers the possibility of applying the "staggering zipper" model to describe conformational transitions in oligomer complexes dA<sub>n</sub>·and dT<sub>n</sub> and dA<sub>n</sub>·2T<sub>n</sub> in the presence of Mg<sup>2+</sup> ions. With the experimental data obtained earlier for the phase diagram of poly dA·poly dT in the presence of Mg<sup>2+</sup> theoretical constants characterizing macromolecule interactions are determined. On the basis of these data and experimental values of transition enthalpy, curves of conformational transformations 3 —&gt; 2 and 2 —&gt; 1 are calculated and the dependences of the transition temperature T<sub>m</sub> and width of transition interval ΔT on the molecule length N, polymer concentration and Mg ion content in solution are evaluated. It is shown that the transition temperature T<sub>m</sub> increases sharply with the molecule length in the range N~10-20 and changes slightly at N&gt;100. The value of T<sub>m</sub> depends linearly on lg[Mg<sup>2+</sup>] and the polymer concentration.</p&gt;}, number={15}, journal={Biophysical Bulletin}, author={Blagoi, Yu.P. and Zozulya, V.N. and Egupov, S.A. and Onyshchenko, V.V.}, year={2005}, month={Jun.}, pages={24-28} }