Interaction of a synthesized pyrene based fluorescent probe with CT-DNA: spectroscopic, thermodynamic and molecular modeling studies

Abstract

The present study demonstrates the synthesis of a new pyrene based water soluble fluorescent probe and its interaction with Calf-thymus DNA. The interaction has been studied using various biophysical methods like absorption and fluorescence spectroscopy, optical melting, isothermal titration colorimetry and circular dichroic studies. Experimental results indicate the binding mode between the probe and DNA to be principally intercalative having a binding energy in the range of −7 to −8 kcal mol⁻¹ and the binding process is favored by both negative enthalpy change and positive entropy change. A salt dependent study revealed that the binding is favored by both small ionic interaction and large nonionic interactions. All the data obtained from biophysical studies have been validated by a molecular modeling study.