A Theoretical Study on the Interaction of Thionine with <i>Micrococcus Lysodeikticus</i> DNA

Abstract

The latest study carried out on binding of small molecules with double stranded deoxyribonucleic acid rec- ommended that the intercalation of thionine, a tricyclic heteroaromatic molecule, with natural double stranded deoxyribo- nucleic acid granted thermal stabilization to the thionine-DNA complex. In this investigation, we reported theoretical analysis of thionine binding with Micrococcus lysodeikticus DNA duplex (Type XI, 72 mol% GC) by using a modified Zimm and Bragg theory, to elucidate the melting behaviour and heat capacity of Micrococcus lysodeikticus DNA with and without thionine binding. For implementing present study, the experimental models of Paul et al.(2010) have been used. The sharpness of transition has been examined in terms of half width and sensitivity parameter (∆H/σ). The conclusion of theo- retical analysis recommended that the different parameters, for example, transition profile, heat capacity curve, sharpness of the transition and half widths are in good agreement with the experimental measurements for interaction of thionine. Thus, the theoretical analysis proposed in this study may be useful to understand interaction of small molecules to deoxyribonucleic acid that may be applied for the designing of prospective DNA binding therapeutic molecules and in the process of drug development.