Elucidation of the effects of lipoperoxidation on the mitochondrial electron transport chain using yeast mitochondria with manipulated fatty acid content.

Autor: Christian Cortés-Rojo, Elizabeth Calderón-Cortés, Mónica Clemente-Guerrero, Mirella Estrada-Villagómez, Salvador Manzo-Avalos, Ricardo Mejía-Zepeda, Istvan Boldogh, Alfredo Saavedra-Molina
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Zdroj: Journal of Bioenergetics & Biomembranes; Feb2009, Vol. 41 Issue 1, p15-28, 14p
Abstrakt: Abstract  Lipoperoxidative damage to the respiratory chain proteins may account for disruption in mitochondrial electron transport chain (ETC) function and could lead to an augment in the production of reactive oxygen species (ROS). To test this hypothesis, we investigated the effects of lipoperoxidation on ETC function and cytochromes spectra of Saccharomyces cerevisiae mitochondria. We compared the effects of Fe2+ treatment on mitochondria isolated from yeast with native (lipoperoxidation-resistant) and modified (lipoperoxidation-sensitive) fatty acid composition. Augmented sensitivity to oxidative stress was observed in the complex III-complex IV segment of the ETC. Lipoperoxidation did not alter the cytochromes content. Under lipoperoxidative conditions, cytochrome c reduction by succinate was almost totally eliminated by superoxide dismutase and stigmatellin. Our results suggest that lipoperoxidation impairs electron transfer mainly at cytochrome b in complex III, which leads to increased resistance to antimycin A and ROS generation due to an electron leak at the level of the QO site of complex III. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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