A water-soluble metal–organic coordination polymer of Zn(II) Schiff base complex in interaction with DNA: diagnosing the mode of binding by in vitro studies

Abstract

In this paper, in vitro DNA binding of a water-soluble metal–organic coordination polymer of Zn(II) Schiff base complex was considered. By focusing on the cooperative effect of multi-Zn(II) centers of the complex, the affinity and mode of binding were investigated by some techniques, e.g., absorption and fluorescence spectroscopy, circular dichroism spectroscopy, viscosity measurement, molecular docking, iodide quenching studies and effect of ionic strength on the complex–DNA binding. The calculated value of Kb = 1.3 × 103 M−1 represented a good affinity of the Zn(II) complex to DNA. From the experimental methods and docking studies, non-classical intercalation (i.e., van der Waals interactions, groove binding or external binding) was proposed as the main mode of binding.