Inhibition of cytochrome c oxidase function by dicyclohexylcarbodiimide.
Inhibition of cytochrome c oxidase function by dicyclohexylcarbodiimide.
复制标题
二环己基碳二亚胺抑制细胞色素 C 氧化酶功能。
DOI：
10.1016/0005-2728(81)90175-4
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Buse,G
中科院分区：
文献类型：
--
作者：
Prochaska,LJ;Bisson,R;Capaldi,RA;Steffens,GC;Buse,G
二环己基碳二亚胺(DCD)与牛心细胞色素氧化酶反应，抑制该酶的质子泵功能，并在较小程度上抑制电子传递。细胞色素氧化酶在洗涤剂分散体或泡膜中的修饰在亚基II-IV中。标记和碎裂研究表明，在亚基III中有一个主要的修饰位点。在亚基II中也有几个位点，在亚基IV中至少有一个位点。亚基III中的主要位点对DCD的专一性至少比其他位点(在亚基II和IV中)大一个数量级。它的修饰可以解释试剂的所有观察到的影响，至少对低浓度的二氯甲烷来说是如此。DCCD对亚基II的标记被芳基细胞色素的共价结合所阻断，芳基细胞色素是一种细胞色素衍生物，它结合到底物的高亲和力结合部位。对亚基III中的主要结合位点进行了测序。该标记是在谷氨酸90中发现的，它由8个氨基酸组成，与线粒体ATP合成酶蛋白脂蛋白中的DCCD结合部位非常相似。
Dicyclohexylcarbodiimide (DCCD) reacted with beef heart cytochromecoxidase to inhibit the proton-pumping function of this enzyme and to a lesser extent to inhibit electron transfer. The modification of cytochromecoxidase in detergent dispersion or in vesicular membranes was in subunits II–IV. Labelling followed by fragmentation studies showed that there is one major site of modification in subunit III. DCCD was also incorporated into several sites in subunit II and at least one site in subunit IV. The major site in subunit III has a specificity for DCCD at least one order of magnitude greater than that of other sites (in subunits II and IV). Its modification could account for all of the observed effects of the reagent, at least for low concentrations of DCCD. Labelling of subunit II by DCCD was blocked by prior covalent attachment of arylazidocytochromec, a cytochromecderivative which binds to the high-affinity binding site for the substrate. The major site of DCCD binding in subunit III was sequenced. The label was found in glutamic acid 90 which is in a sequence of eight amino acids remarkably similar to the DCCD-binding site within the proteolipid protein of the mitochondrial ATP synthetase.