[Ion-exchange properties of immobilized DNA: influence of the polymer concentration and the solvent nature on the exchange of alkali metals].
The method of ion exchange on immobilized DNA, which allows to determine quantitative parameters of ion binding with a high precision, is used for studying of DNA ion selectivity. Insoluble ion exchangers on the DNA basis with the exchange capacity of 0.09 and 0.17 mg-equiv. per 1 g of dry gel are synthesized by means of immobilization of DNA gel in polyacrylamide gel. Constants of ion-exchange equilibrium for the exchanges K+-Na+ and K+-Li+ are determined on these exchangers in water and 50% water-dioxane solution. It is shown that DNA binds selectively only Li+. The selectivity to Li+ increases with the increase of DNA concentration in gel. The specific properties of Li+-DNA in solutions and in the solid state, for example, the impossibility of the B-A transition, are discussed. The selectivity reversal in favor of K+ is observed in water-dioxane solution. The cause of the selectivity reversal and the question of possible participation of cell polyelectrolytes in creation of ion gradients in the living cell are discussed.
D000818:Animals; D002414:Cations, Monovalent; D002645:Chickens; D004247:DNA; D004912:Erythrocytes; D007475:Ion Exchange Resins; D007700:Kinetics; D009690:Nucleic Acid Conformation
D002414:Cations, Monovalent; D007475:Ion Exchange Resins; D004247:DNA
Ionoobmennye svoĭstva immobilizovannoĭ DNK: vliianie kontsentratsii polimera i prirody rastvoriteliia na obmen ionov shchelochnykh metallov.