Spectroscopic and computational studies on the interaction of DNA with pregabalin drug

The interaction of the drug pregabalin (S-3-(aminomethyl)-5-methylhexanoic acid) with CT-DNA was studied by using fluorescence spectroscopy, UV-Vis, CD, molecular docking study and viscometery. The fluorescence and UV absorption spectroscopy indicated that the drug interacted with CT-DNA in a groove binding mode. The binding constant and the number of binding sites were 5.6×10(4)Lmol(-1) and 0.96, respectively. The fluorimetric studies showed that the reaction between the drug and CT-DNA is exothermic (ΔH=33.11kJmol(-1); ΔS=48.84Jmol(-1)K(-1)). Furthermore, the drug does not induce any changes in DNA viscosity. Circular dichroism spectroscopy (CD) was employed to measure the conformational changes of CT-DNA in the presence of the drug, which verified the groove binding mode. The molecular modeling results illustrated that the drug binds to groove of DNA by relative binding energy of docked structure -21.9kJmol(-1).