Direct photo-induced DNA strand scission by a ruthenium bipyridyl complex
| Autor: | Lev Weiner, Eylon Yavin, Abraham Shanzer, Rina Arad-Yellin, Eric D. A. Stemp, Irit Sagi |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Electrophoresis
Agar Gel Gel electrophoresis Light Guanine Radical Electron Spin Resonance Spectroscopy chemistry.chemical_element Microscopy Atomic Force Photochemistry Biochemistry Ruthenium Adduct law.invention Inorganic Chemistry Kinetics chemistry.chemical_compound 2 2'-Dipyridyl chemistry law Fragmentation (cell biology) Electron paramagnetic resonance DNA Plasmids |
| Zdroj: | Journal of Inorganic Biochemistry. 98:1750-1756 |
| ISSN: | 0162-0134 |
| DOI: | 10.1016/j.jinorgbio.2004.07.016 |
| Popis: | Irradiation of plasmid DNA in the presence of Ru(II)-2, a modified tris(2,2'-bipyridyl)Ru(II) complex, in which two hydroxamic acid groups are attached to one of the three bipyridyl ligands, results in total fragmentation of the DNA. The photo-chemical reaction products were analyzed by gel electrophoresis, which revealed complete fragmentation. Further evidence for the complete degradation of the DNA was obtained by imaging the pre- and post-treated plasmid DNA using atomic force microscopy (AFM). A mechanism for the reaction is proposed. It initially involves the photo-chemical generation of Ru(III) ions and superoxide radicals, as corroborated by absorbance difference spectroscopy and electron paramagnetic resonance (EPR). Consequently, Ru(III) preferentially oxidizes guanine, liberating superoxide radicals that yield OH radicals. The OH radicals were identified by observing the spectral change at 532 nm of a 5'-dAdG substrate forming a colored adduct with thiobarbituric acid. These radicals are associated with the major non-specific damage exerted to DNA. |
| Databáze: | OpenAIRE |
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