title: [Interaction of Cu2+ and Ca2+ ions with DNA immobilized in polyacrylamide gel].
abstract: Interaction of cupric and calcium ions with DNA entrapped in acrylamide gel was studied by means of ion-exchange method. Ion-exchangers on the basis of DNA were obtained by polymerization of acrylamide with and without warming-up. Samples of DNA with different degrees of denaturation were also used for preparation of ion-exchangers. It was demonstrated that ion-exchange capacity is determined by the number of phosphate groups of DNA entrapped in gel. Cu2+ and Ca2+ ion-exchange equilibrium on the macromolecules of immobilized DNA was studied at different temperatures. Ion-exchange equilibrium constant alpha Cu2+ Ca2+ was shown to vary from 1,9 to 8,2 an increase of selectivity for Cu2+ ions taking place under conditions favouring denaturation of DNA. Stoichiometric ratio between the quantity of the phosphate groups and the number of equivalents of Cu2+ and Ca2+ was observed in all the experiments. Lack of over-equivalent absorption of CuCl2 on the DNA molecules indicates that chloride ions do not participate in charge neutralization within the Cu2+.DNA complex. It means that Cu2+ ions interact with phosphate groups of DNA coordinate simultaneously with DNA bases only.
mesh_terms: D000180:Acrylic Resins; D002118:Calcium; D055598:Chemical Phenomena; D002621:Chemistry; D003300:Copper; D004247:DNA; D007474:Ion Exchange; D007477:Ions; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D007477:Ions; C016680:polyacrylamide gels; D003300:Copper; D004247:DNA; D002118:Calcium
vernacular_title: Vzaimodeĭstvie ionov Cu2+ i Ca2+ s DNK, immobilizovannoĭ v poliakrilamidnom gele.