G-quadruplex vs. duplex-DNA binding of nickel(II) and zinc(II) Schiff base complexes
Riccardo Bonsignore, Alessio Terenzi, Angelo Spinello, Annamaria Martorana, Antonino Lauria, Anna Maria Almerico, Bernhard K. Keppler, Giampaolo Barone
Journal of Inorganic Biochemistry
Novel nickel(II) (1) and zinc(II) (2) complexes of a Salen-like ligand, carrying a pyrimidine ring on the N,N’ bridge, were synthesized and characterized. Their interaction with duplex and Gquadruplex DNA was investigated in aqueous solution through UV-visible absorption, circular dichroism and viscometry measurements. The results obtained point out that, while the zinc(II) complex does not interact with both duplex and G-quadruplex DNA, the nickel(II) complex 1 binds preferentially to G-quadruplex respect to duplex-DNA, with values of the DNA-binding constants, Kb, 2.6✕105 M -1 and 3.5✕104 M -1 , respectively. Molecular dynamics simulations provided an atomic level model of the top-stacking binding occurring between 1 and hTelo Gquadruplex.
Circular dichroism, DNA structure, Ligand binding, Inorganic chemistry, Biochemistry