Cleavage of DNA by model complexes of cytochrome P-450.
Thiolate-hemin complexes as chemical models for cytochrome P-450 have been shown to cause cleavage of DNA. The cleavage of DNA to open-circular and linear forms depended on the structure of thiol ligand and the thiol ligand:hemin ratio at pH 7.8. Complete cleavage of DNA was observed by complexes containing thioglycolate ethylester and mercaptoethanol at 400-600 moles excess of thiol ligand to hemin, those containing cysteine, cysteine methylester and cysteine ethylester at 50-200 moles excess, and those containing mercaptopropionylglycine, glutathione, glutathione dimethylester, penta- and nonapeptides at 5-100 moles excess. Inhibition experiments suggested the involvement of active oxygen species in the cleavage of DNA.
D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D006868:Hydrolysis; D008954:Models, Biological
D004247:DNA; D003577:Cytochrome P-450 Enzyme System