Marres C A, De Vries S, Slater E C
Biochim Biophys Acta. 1982 Aug 20;681(2):323-6. doi: 10.1016/0005-2728(82)90039-1.
In 5,5'-dithiobis(2-nitrobenzoate) (DTNB)-treated succinate: cytochrome c reductase, the electron transfer from duroquinol to cytochrome c is inhibited due to the fact that the Rieske Fe-S cluster and, consequently, cytochrome, c, are no longer reducible by substrate. The finding that, after this treatment, cytochrome b is still reducible by substrate in the absence of antimycin, but not in its presence, is consistent with a Q-cycle mechanism for the electron transfer through QH2:cytochrome c oxidoreductase. The inhibitory effect of DTNB and its effect on the EPR spectrum of the [2Fe-2S] cluster suggest that it prevents either the binding of ubiquinone in the vicinity of this cluster or the interaction between the Fe-S protein and a ubiquinone-binding protein.
在5,5'-二硫代双(2-硝基苯甲酸)(DTNB)处理的琥珀酸：细胞色素c还原酶中，由于里斯克铁硫簇以及因此细胞色素c不再能被底物还原，从杜罗醌醇到细胞色素c的电子传递受到抑制。在这种处理后，细胞色素b在没有抗霉素的情况下仍可被底物还原，但在有抗霉素的情况下则不能，这一发现与通过QH2：细胞色素c氧化还原酶进行电子传递的Q循环机制一致。DTNB的抑制作用及其对[2Fe-2S]簇的电子顺磁共振光谱的影响表明，它要么阻止了泛醌在该簇附近的结合，要么阻止了铁硫蛋白与泛醌结合蛋白之间的相互作用。
