ABSTRACT
The ability of a synthetic, aromatic tripeptide, H-Phe-Phe-Phe-OH (FFF) to recognize the double-stranded DNA (dsDNA) has been tested with various biophysical and thermodynamic techniques. From the study, it is established that the peptide can recognize the groove of the ct-DNA and the binding constant value calculated from the isothermal titration calorimetric (ITC) study at 25°C is 9.96 × 103 M-1. From ITC data it is also noticed that the peptide–DNA complexation is favored by positive standard molar entropy contribution (TΔS°) of 13.65 kJ mol−1 and negative standard molar enthalpy contribution (ΔH°) of −9.170 kJ mol−1. The temperature-dependent ITC study also shows that the equilibrium constant value decreases gradually with increasing temperature. However, the standard molar Gibbs energy change exhibits only minor alterations suggesting the occurrence of enthalpy-entropy compensation. The studies reveal the insight into the spectroscopic and thermodynamic prospect of the FFF-ct-DNA interaction in vitro and hold the promise of future applications as DNA targeting drug.