Efficient double-strand cleavage of DNA mediated by Zn(II)-based artificial nucleases

Two water-soluble zinc complexes, [Zn(L)Cl-2] (1) and [Zn-2(L)(2)(mu-C2O4)(H2O)(2)]center dot(ClO4)(2)center dot CH3OH (2) (L = N,N-bis(2-pyridylmethyl)methylamine), were prepared to serve as nuclease mimics. The complexes were characterized by X-ray, IR and UV-vis spectroscopy as well as ESI-MS. The electrospray mass spectrum of 2 in solution indicates that dinuclear ion [Zn-2(L)(2)(mu-C2O4)(ClO4)](+) (3) is the active species. UV-Vis absorption and fluorescence spectroscopy studies show that the complexes partially intercalate to CT-DNA. In the absence of reducing agent, supercoiled plasmid DNA cleavage by the complexes 1 and 3 was performed and the hydrolytic mechanism was demonstrated by adding standard radical scavengers.