1. DNA cleavage activity of VIVO(acac)2 and derivatives
- Author
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João P. Telo, Sofia Gama, Ofelia Nouri, Ana Isabel Tomaz, Virtudes Moreno, Vera Ribeiro, Isabel Cavaco, Esther Escribano, João Costa Pesssoa, and Nataliya Butenko
- Subjects
Tris ,Stereochemistry ,Radical ,Hydroxybutyrates ,Vanadium complexes ,Microscopy, Atomic Force ,Cleavage (embryo) ,Biochemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Pentanones ,Organic chemistry ,Vanadyl acetylacetonate ,DNA Cleavage ,HEPES ,Nuclease ,DNA cleavage ,biology ,Circular Dichroism ,Hydrolysis ,Electron Spin Resonance Spectroscopy ,DNA ,Hydrogen Peroxide ,Hydrogen-Ion Concentration ,MOPS ,Inorganic nucleases ,Kinetics ,chemistry ,Phosphodiester bond ,biology.protein ,Reactive Oxygen Species - Abstract
The DNA cleavage activity of several beta-diketonate vanadyl complexes is examined. Vanadyl acetylacetonate, V(IV)O(acac)(2), 1, shows a remarkable activity in degrading plasmid DNA in the absence of any activating agents, air and photoirradiation. The cleaving activity of several related complexes V(IV)O(hd)(2) (2, Hhd=3,5-heptanedione), V(IV)O(acac-NH(2))(2) (3, Hacac-NH(2)=acetoacetamide) and V(IV)O(acac-NMe(2))(2) (4, Hacac-NMe(2)=N,N-dimethylacetoacetamide) is also evaluated. It is shown that 2 exhibits an activity similar to 1, while 3 and 4 are much less efficient cleaving agents. The different activity of the complexes is related to their stability towards hydrolysis in aqueous solution, which follows the order 1 approximately 23 approximately 4. The nature of the pH buffer was also found to be determinant in the nuclease activity of 1 and 2. In a phosphate buffered medium DNA cleavage by these agents is much more efficient than in tris, hepes, mes or mops buffers. The reaction seems to take place through a mixed mechanism, involving the formation of reactive oxygen species (ROS), namely OH radicals, and possibly also direct cleavage at phosphodiester linkages induced by the vanadium complexes.
- Published
- 2009