Complete inhibition of electron transfer from ubiquinol to cytochrome b by the combined action of antimycin and myxothiazol
Complete inhibition of electron transfer from ubiquinol to cytochrome b by the combined action of antimycin and myxothiazol
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DOI：
10.1016/0014-5793(81)81206-9
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发表时间：
1981-12
期刊：
影响因子：
3.5
通讯作者：
G. von Jagow;W. Engel
中科院分区：
文献类型：
--
作者：
G. von Jagow;W. Engel
氧化磷酸化是通过质子易位（穿过膜）与氧化还原等价物（从底物到最终氧的矢量）的流动建立的[11]。这种流动由氢原子和电子的交替转移组成。氢原子由两个电子载体运输，如黄素酶和泛醌;电子由一个电子载体运输，如铁硫蛋白和细胞色素。这种从两个氧化还原当量的氢原子载体（即泛醌）到一个氧化还原当量的电子载体（即细胞色素B）的转换发生在复合物III（泛醌醇：细胞色素c还原酶）[2]。本研究旨在进一步了解呼吸链细胞色素bci段中电子载体的排列。实验进行了亚线粒体颗粒和分离的复合物III从牛心。研究了抗霉素和一种新的抗真菌抗生素粘噻唑的作用。已证明Myxothiazol属于新型moa抑制剂，即含有E-/3-甲氧基丙烯酸酯作为基本结构段的抑制剂[5]。发现Myxothiazol与不同于抗霉素结合位点的位点结合[3，4]。这些实验仅限于电子转移机理，而没有考虑质子转移。测试了与细胞色素B的不同位点结合的2种抑制剂抗霉素和粘噻唑是否联合收割机在它们对从泛醇到细胞色素B的电子转移的抑制作用中。
Oxidative phosphorylation is established by a link of proton translocation (across a membrane) to the flow of redox equivalents (vectorially from the substrates to finally oxygen)[11. This flow consists of an alternating transfer of hydrogen atoms and electrons. The hydrogen atoms are transported by two electron carriers, eg, flavoenzymes and ubiquinone; the electrons are transported by one-electron carriers, eg, iron-sulfur proteins and cytochromes. Such a switch from a two-redoxequivalent hydrogen atom carrier, namely ubiquinone, to a one-redoxequivalent electron carrier, namely cytochrome b, takes place at complex III, the ubiquinol: cytochrome c reductase [2]. This study was performed to obtain further insight into the arrangement of the electron carriers in the cytochrome bci segment of the respiratory chain. The experiments were carried out with submitochondrial particles and with the isolated complex III from beef heart. The action of antimycin and of a new antifungal antibiotic, myxothiazol [3, 4] was investigated. Myxothiazol has been shown to belong to the novel moa-inhibitors, ie, inhibitors containing E-/3-methoxyacrylate as an essential structural segment [5]. Myxothiazol was found to bind to a site different from the antimycin binding site [3, 4]. These experiments are restricted to the mechanism of electron transfer, while the proton transfer was not taken into consideration. It was tested whether the 2 inhibitors antimycin and myxothiazol, binding to different sites of cytochrome b, combine in their inhibitory action on the electron transfer from ubiquinol onto cytochrome b.