Inhibition of the mitochondrial bc1 complex by dibromothymoquinone
- 30 May 1983
- journal article
- Published by Wiley in FEBS Letters
- Vol. 156 (1) , 15-19
- https://doi.org/10.1016/0014-5793(83)80238-5
Abstract
We have studied the effects of dibromothymoquinone (DBMIB) in various redox activities of the succinate—cytochrome c span of the mitochondrial respiratory chain. At concentrations higher than 50 mol/mol of cytochrome c 1 the inhibitor produces a bypass of electron transfer on the substrate side of the bc 1 complex, because of its autooxidation capability. This induces an artifactual overestimation of the real inhibition titer of the redox activity of this enzyme, which has been found to be 3–6 mol/mol of cytochrome c 1 by following the ubiquinol—cytochrome c reductase activity. This action is reversed by addition of excess of sulphydryl compounds like cysteine.Keywords
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