Spectroscopic studies on the interaction of calf thymus DNA with the drug levetiracetam

Abstract

The interaction of native calf thymus DNA with the drug levetiracetam (LV) has been investigated by absorption, emission, circular dichroism, melting temperature (Tm) curves and viscosity studies. Spectrophotometric studies of the interaction of levetiracetam with DNA have shown that it can binds to CT-DNA and the DNA binding constant (Kb=(4.9±0.2)×103M−1) is comparable to groove binding drugs. Competitive fluorimetric studies with hoechst 33258 have shown that levetiracetam exhibit the ability to displace the DNA-bound hoechst 33258 indicating that it binds to DNA in strong competition with hoechst 33258 for the groove binding. Furthermore, the drug induces detectable changes in the CD spectrum of CT-DNA as well as changes in its viscosity. The values of melting temperature (Tm) of DNA–methylene blue (MB) complex and LV–DNA–MB complex were determined. Finally, all of the experimental results prove that the minor groove binding must be predominant.