DNA-interacting properties of two analogous square-planar cis-chlorido complexes: copper versus palladium

Abstract

Two square-planar coordination compounds, namely [Cu(CPYA)Cl2] (1) and [Pd(CPYA)Cl2] (2), were prepared from the ligand 4-chloro-N-(pyridin-2-ylmethyl)aniline (CPYA) and two chloride salts, and were fully characterized, including by X-ray diffraction. Spectroscopic, electrophoretic and AFM studies revealed that the two isostructural compounds were interacting differently with DNA. In both cases, the initial interaction involves electrostatic contacts of the CPYA ligand in the minor groove (as suggested by molecular docking), but subsequent strong binding occurs with the palladium(II) complex 2, whereas the binding with the copper complex 1 is weaker and concentration dependent. The strong binding of 2 eventually leads to the cleavage of the double strand and the redox activity of 1 allows to oxidatively cleave the biomolecule. Graphic abstract

Minimal Functionalization of Ruthenium Compounds with Enhanced Photoreactivity against Hard-to-Treat Cancer Cells and Resistant Bacteria

“…This profile suggests that the metal complex-DNA interaction induces a structural modification of the DNA. 66,67 Curiously, GRBA did not show major changes in the CD spectrum of CT DNA, neither in the positive nor in the negative bands, but it exhibited modest changes in the intensity of CD signals. This behavior is in agreement with our previous unsuccessful attempts to measure DNA interaction with this metal compound.…”

“…In the negative band, there is also a decrease in intensity, indicating a loss of the right-handed helix. This profile suggests that the metal complex-DNA interaction induces a structural modification of the DNA. , …”

Anti-toxoplasma activity and DNA-binding of copper(II) and zinc(II) coordination compounds with 5-nitroimidazole-based ligands

“…Distinct forms of pBR322 plasmid DNA are commonly observed by gel electrophoresis due to the conformational changes that present distinct electrophoretic mobility: (1) supercoiled DNA (Form I) that migrates faster on the gel, (2) circular nicked (Form II), obtained from a one-strand scission, has a slower migration through the gel and (3) linear form (Form III) is generated when both strands are cleaved and migrates between forms I and II [ 54 ]. The interaction of the free ligands and their copper(II) and zinc(II) coordination compounds with pBR322 was investigated in presence of H 2 Asc (50 μM) as reducing agent and H 2 O 2 (500 μM) as ROS generator.…”

Low-Dimensional Compounds Containing Bioactive Ligands. Part XX: Crystal Structures, Cytotoxic, Antimicrobial Activities and DNA/BSA Binding of Oligonuclear Zinc Complexes with Halogen Derivatives of 8-Hydroxyquinoline

“…We tried to examine the actual binding mode of the Zn(II) complexes with DNA by competitive fluorometric dye displacement assay with Ethidium bromide (EB) also. EB is often used as a DNA intercalating agent, which displays maximum emission at about 602 nm upon binding to double helical DNA [34]. The fluorescence emission spectra of the DNA-EB system was measured from 565 nm to 700 nm with incremental amounts of complexes 1-3 (Figures S10 and S11 and Figure 12).…”