线粒体呼吸链膜蛋白复合体的结构

Structure of mitochondrial respiratory membrane protein complexes

线粒体作为真核细胞的重要"能量工厂",是细胞进行呼吸作用的场所,呼吸作用包括柠檬酸循环和氧化磷酸化两个过程,其中氧化磷酸化过程的电子传递链(又称线粒体呼吸链)位于线粒体内膜上,由四个相对分子质量很大的跨膜蛋白复合体(Ⅰ、Ⅱ、Ⅲ、和Ⅳ)、介于Ⅰ/Ⅱ与Ⅲ之间的泛醌以及介于Ⅲ与Ⅳ之间的细胞色素c共同组成。线粒体呼吸链的功能是进行生物氧化,并与称之为复合物V的ATP合成酶(磷酸化过程)相偶联,共同完成氧化磷酸化过程,并生产能量分子ATP。线粒体呼吸链的结构生物学研究对于彻底了解电子传递和能量转化的机理是至关重要的,本文分别论述线粒体呼吸链复合体Ⅰ、Ⅱ、Ⅲ和Ⅳ的结构,并跟踪线粒体呼吸链超复合体的结构研究进展。

As the important ＂energy factory＂ of eukaryotic cells, mitochondrion is the place for cellular respiration that includes citric acid cycle and Oxidative phosphorylation process （OXPHOS）. The OXPHOS electron transfer chain （mitochondrial respiration chain） is located on the inner membrane of mitochondrion and comprising of four large trans-inembrane protein complexes （mitochondrial respiratory Complex I, II, III and IV） as well as ubiquinone between Complex I/II and III and cytochrome c between Complex III and IV. The function of mitochondrial respiration chain is biological oxidation which is coupled with phosphorylation by ATP synthesis enzyme （ATPase, called Complex V） and then complete OXPHOS producing energy molecule ATP. Structural researches on those membrane protein complexes in mitochondrial respiration chain are very important for understanding the mechanisms of electron transfer and energy transformation. Here we reviewed the structural studies of mitochondrial respiratory complexes respectively as well as the structural research progresses on their respiratory supra complexes.