Chemically and photochemically initiated DNA cleavage by an insulin-mimeticbisperoxovanadium complex

Chemically and photochemically induced cleavage of DNA by the insulin-mimetic compound NH₄[VO(O₂)₂-(1,10-phenanthroline)], bpV(phen), have been studied.⁵¹V NMR and absorption indicate that photoirradiation with low energy UV light of aqueous solutions containing bpV(phen) leads to the conversion of the compound to simple vanadates. Photoillumination of the compound in the presence of supercoiled pBR322 DNA results in cutting of the plasmid to produce nicked circular and linear DNA. Quantitative analysis of agarose gel data shows that bpV(phen) is a single strand nicking agent exhibiting sequence and/or base specificity.