G4-DNA vs. B-DNA binding of Schiff base transition metal complexes

The competitive binding of nickel(II), copper(II) and zinc(II) complexes toward B- and G4-DNA was addressed through spectroscopic titrations and rationalized by computational investigations, consisting of molecular dynamics simulations followed by density functional theory/molecular mechanics (DFT/MM) calculations [1]. The experimental DNA binding studies clearly highlight the selectivity of the compounds, in particular the nickel(II) complex, toward G4-DNA from both h-Telo and c-myc. Moreover, the compounds show biological activity against HeLa and MCF-7 cancer cell lines. Remarkably, the experimental DNA-binding affinity trend of the three metal complexes, obtained from the DNA-binding constants as ΔG°=−RT ln(Kb), is reproduced by the Gibbs formation free energy calculated by DFT/MM for the DNA-binding complexes, in the implicit water solution.