The study of metallic  metallic complexes and their interaction with DNA is gradually increasing because of their importance in biotechnology and medicine. These compounds may be used in the development of new therapeutics as antitumor and antibiotic drugs, in molecular biology and as biochemical and biotechnological probes. In this work interaction of a novel trinuclear copper (II) complex, synthetized as a cathecol oxidase biomimetic model, with DNA molecule was analyzed. The DNA cleavage analysis was done by incubating the complex in different concentrations (0.5 ; 2.0 ; 10.0 ; 25.0 and 50.0mM) with the plasmid pBSK-II at 50° C for 16 hours in 100mM PIPES pH 7,0. These samples were submitted to agarose gel electrophoresis with ethidium bromide and the resulting gels were analyzed with a photodocumentation system and were quantified using Labworks software. Results have shown this complex is very active in DNA cleavage generating nicked and linear plasmid DNA. The last demonstrating double strand DNA cleavage, a rare phenomenon scarcely observed for these kinds of complexes. Cleavage reactions were also performed in the presence of  DMSO (dimethyl sulfoxide), a free radical scavenger, to evaluate the role of reactive oxygen species in DNA cleavage by this complex. Since double strand DNA cleavage is promptly generated upon incubation with very low complex concentration (0.5mM), this trinuclear copper (II) complex could be considered a potentially important chemical nuclease.
Financial support: CNPq, MCT, FAPESC