Investigation on the interaction of DNA and electroactive ligands using a rapid electrochemical method

Abstract

A rapid method for investigation of the interaction of DNA and electroactive ligands based on an electrochemical equation for irreversible processes is presented. The binding constant ( K) and the size of binding site ( s) are simultaneously obtained from the dependence of the current on the amount of added DNA in voltammetry. A non-intercalative binder (Hoechst 33258) and two DNA-intercalators (mitoxantrone (MXT) and actinomycin D (AMD)) were examined in experiments. It was found that the binding constant of Hoechst 33258, mitoxantrone and actinomycin D, were 2.1×10 8, 8.9×10 9 and 9.1×10 9 cm 3 mol −1; and the size of their binding sites were 4, 3 and 8, respectively. The study provides a convenient and sensitive approach for estimating affinity parameters and outlining the interaction between DNA and electroactive targeting compounds.