| | 1 | Author
| EvaP. Aur, RichardJ Y Oungm An, E. Dm, L. En, G. Feld Er, ErichF E Lstner | Requires cookie* | | | Title
| Mechanisms of Adriamycin-Dependent Oxygen Activation Catalyzed by NADPH-Cytochrome c*-(Ferredoxin)-Oxidoreductase  | | | | Abstract
| Under aerobic conditions, 0 2 uptake and production o f 0 2~ and H 20 2 by isolated N A D P H -cytochrome c-(ferredoxin)-oxidoreductase from Euglena gracilis was strongly stim ulated by adriamycin. Further stim ulation was not observed with 0.1 m M F e 3+-EDTA. M ethionine fragmentation (measured as ethylene release), as a reliable indicator for the formation o f O H ' radical-like oxidants under aerobic conditions (1 0 0 |im o l 0 2 in a 10 ml reaction vessel) was strongly stimulated by 0.1 m M F e3+-ED TA or, in the absence o f iron, by partial anaerobiosis (1 (irnol 0 2 per vessel). The highest rate o f m ethionine fragm entation was observed under an aerobic conditions in the presence o f both reduced adriam ycin and added H 20 2. Aerobic methionine fragmentation in the presence o f adriam ycin and F e3+-ED TA was inhibited by superoxide dismutase and catalase by m ore than 90%, w hile m ethionine fragmen tation under semianaerobiosis in the absence o f F e 3+-E D T A was inhibited by superoxide dismutase to only about 50%, while catalase again inhibited by m ore than 90%. These results indicate that the adriamycin-catalyzed production o f a strong oxidant appears to be governed by different mechanisms depending on oxygen availability; nam ely the production o f a Fenton-type oxidant driven by adriamycin-catalyzed superoxide form ation and also, the formation o f the "crypto-OH' radical" by direct electron donation from the adriam ycin sem iquinone radical to H20 2 under oxygen limiting conditions. | | | |
Reference
| Z. Naturforsch. 39c, 261—267 (1984); received D ecem ber 15 1983 | | | |
Published
| 1984 | | | |
Keywords
| Adriamycin, Oxygen Activation, Oxygen Toxicity, Superoxide, H ydroxyl Radical | | | |
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| default:Reihe_C/39/ZNC-1984-39c-0261.pdf | | | | Identifier
| ZNC-1984-39c-0261 | | | | Volume
| 39 | |
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