Chomyn A, Patel S D, Cleeter M W, Ragan C I, Attardi G
Division of Biology, California Institute of Technology, Pasadena 91125.
J Biol Chem. 1988 Nov 5;263(31):16395-400.
The site of synthesis of the iron-sulfur subunits of the flavoprotein and iron-protein fractions of the human respiratory chain NADH dehydrogenase has been investigated to test the possibility that any of them is synthesized in mitochondria. For this purpose, antibodies specific for individual subunits of the bovine enzyme, which cross-reacted with the homologous human subunits in immunoblot assays, were tested against HeLa cell mitochondrial proteins labeled in vivo with [35S]methionine in the absence or presence of inhibitors of mitochondrial or cytoplasmic protein synthesis. The results clearly indicated that all the iron-sulfur subunits of the flavoprotein and iron-protein fractions of human complex I are synthesized in the cytosol and are, therefore, encoded in nuclear genes.
对人类呼吸链NADH脱氢酶黄素蛋白和铁蛋白组分中铁硫亚基的合成位点进行了研究，以检验它们是否在线粒体中合成。为此，在存在或不存在线粒体或细胞质蛋白质合成抑制剂的情况下，用[35S]甲硫氨酸对HeLa细胞线粒体蛋白质进行体内标记，然后用针对牛酶单个亚基的特异性抗体（在免疫印迹分析中与同源人类亚基发生交叉反应）进行检测。结果清楚地表明，人类复合物I的黄素蛋白和铁蛋白组分的所有铁硫亚基均在细胞质中合成，因此由核基因编码。
