Interaction of benzidine with DNA: experimental and modelling studies

Interaction of benzidine with DNA has been studied using spectroscopic and molecular simulation techniques. A binding constant of (6.2±0.4)×103 M−1 has been obtained by spectroscopic technique for benzidine, which indicates the existence of weak interaction between benzidine and DNA. The experimental analysis including spectroscopic and viscometric techniques reveal the possibility of groove as well as partial intercalation mode of binding of benzidine with DNA. The calculated binding energy for minor groove and intercalated complex from modelling studies are 64.15 and 67.27 kcal/mol, respectively. The calculations clearly bring out the significance of non-bonding interactions between DNA and benzidine. Both experimental and modelling studies show that benzidine interacts with DNA through minor groove binding as well as partial intercalation mechanism.