Identification of human mitochondrial metabolome proteins

(Aim)线粒体DNA（mtDNA）编码线粒体电子传递系统所必需的基因。最近我们提出线粒体DNA具有一个大的蛋白质-DNA复合物，称为类核，而类核结构对线粒体DNA的维持至关重要。线粒体转录因子A（TFAM）是类核的主要成分。在这项研究中，我的目的是确定蛋白质成分的类核LC/MS/MS。（方法）用交联剂处理离体人线粒体。溶解后，用抗TEAM抗体免疫沉淀类核。沉淀的蛋白质在一维SDS-PAGE上分离，提取，胰蛋白酶化，并通过LC/MS/MS分析。（结果）1）潜在的DNA或RNA结合蛋白; 2）热休克蛋白; 3）核糖体蛋白; 4）TCA循环相关蛋白; 5）脂肪酸β氧化酶。这些结果表明，线粒体类核为脂肪酸的翻译、TCA循环和β氧化的有效代谢提供了支架。

(Aim) Mitochondrial DNA (mtDNA) encodes genes essential for the mitochondrial electron transfer system. Recently we proposed that mtDNA takes on a large protein-DNA complex called nucleoid and the nucleoid structure is critical for maintenance of mtDNA. Mitochondrial transcription factor A (TFAM) is a main component of the nucleoid. In this study, I aim to identify protein components of the nucleoid by LC/MS/MS.(Methods) Isolated human mitochondria were treated with a c ross-linker. After solubilization, the nucleoid was immunoprecipitated with anti-TEAM antibody. The precipitated proteins were separated on one dimensional SDS-PAGE, extracted, tripsinized, and and analyzed by LC/MS/MS.(Results)1)Potential DNA- or RNA binding proteins2)Heat shock proteins3)Ribosomal proteins4)TCA cycle related proteins5)Enzymes for β oxidation of fatty acidsAll proteins identified were classified into only 5 groups as above. These results suggest that the mitochondrial nucleoid provides a scaffold for efficient metabolism of translation, TCA cycles, and β oxidation of fatty acids.