The identification of the site of action of dicyclohexylcarbodi-imide as a proteolipid in mitochondrialmembranes.
The identification of the site of action of dicyclohexylcarbodi-imide as a proteolipid in mitochondrialmembranes.
复制标题
线粒体膜中二环己基碳二亚胺作为蛋白脂质的作用位点的鉴定。
作者：
K. J. Cattell;C. Lindop;I. G. Knight;R. B. Beech
用NN′-双环己基[14C]碳二亚胺孵育线粒体膜，对氧化磷酸化的部分反应有95-100%的不可逆抑制作用。在聚丙烯酰胺凝胶上对膜溶液进行分析。从凝胶中回收的放射性物质中，90%被证明与一个分子量约为10000的蛋白质有关。用氯仿-甲醇混合物萃取使放射性蛋白和相关磷脂从膜中溶解，并用Sephadex LH-20进行溶剂分离和吸附层析，浓缩50倍。用Sephadex LH-20层析获得多个蛋白放射性峰。然而，每个峰中90-100%的放射性被证明与膜溶液电泳图中观察到的主要放射性蛋白相似的单一蛋白质有关。结果表明，二环己基碳酰亚胺通过与氯仿-甲醇-可溶性蛋白上的一个基团共价反应抑制线粒体氧化磷酸化。讨论了该蛋白在氧化磷酸化中的可能作用。
Mitochondrial membranes were incubated with NN′-dicyclohexyl[14C]carbodi-imide, which irreversibly inhibited the partial reactions of oxidative phosphorylation by 95–100%. Solutions of the membranes were analysed on polyacrylamide gels. Of the radioactivity recovered from the gels 90% was shown to be associated with a single protein of molecular weight about 10000. The radioactive protein and associated phospholipid was solubilized from the membrane by extraction with chloroform–methanol mixtures and was concentrated 50-fold by solvent fractionation and adsorption chromatography on Sephadex LH-20. Several protein–radioactivity peaks were obtained by Sephadex LH-20 chromatography. However, 90–100% of the radioactivity in each peak was shown to be associated with a single protein similar to the major radioactive protein observed in electrophoretograms of the membrane solutions. It is concluded that dicyclohexylcarbodi-imide inhibits mitochondrial oxidative phosphorylation by reacting covalently with a group on this chloroform–methanol-soluble protein. The possible role of this protein in oxidative phosphorylation is discussed.