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

Abstract

Two water-soluble zinc complexes, [Zn(L)Cl₂] (1) and [Zn₂(L)₂(μ-C₂O₄)(H₂O)₂]·(ClO₄)₂·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 [Zn₂(L)₂(μ-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.