Catalase enhances damage to DNA by bleomycin-iron(II): the role of hydroxyl radicals.
Bleomycin degrades DNA under aerobic conditions when a ferrous salt is added. This reaction is enhanced by catalase and certain hydroxyl radical scavengers but inhibited by the addition of hydrogen peroxide. A ferricbleomycin complex is, however, stimulated by addition of hydrogen peroxide. These findings suggest that catalase removes hydrogen peroxide and in so doing prevents loss of ferrous ions and formation of hydroxyl radicals (OH.) by a Fenton-type reaction. It further suggests that OH. radicals, when formed, are more involved in the inactivation of bleomycin than in the release of thiobarbituric acid reactive material from DNA.
J M
JM
Gutteridge
A P
AP
Beard
G J
GJ
Quinlan
D000818:Animals; D001761:Bleomycin / Q000494:pharmacology* / Q000031:analogs & derivatives; D002374:Catalase / Q000494:pharmacology*; D002417:Cattle; D004247:DNA / Q000378:metabolism*; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006878:Hydroxides / Q000378:metabolism*; D017665:Hydroxyl Radical; D066298:In Vitro Techniques
D005609:Free Radicals; D006878:Hydroxides; C023503:iron bleomycin; D001761:Bleomycin; D017665:Hydroxyl Radical; D004247:DNA; D006861:Hydrogen Peroxide; D002374:Catalase