Takamiya S, Wang H, Hiraishi A, Yu Y, Hamajima F, Aoki T
Department of Parasitology, Juntendo University School of Medicine, Tokyo, Japan.
Arch Biochem Biophys. 1994 Jul;312(1):142-50. doi: 10.1006/abbi.1994.1292.
The respiratory chain of adult Paragonimus westermani, a lung fluke, was characterized in isolated mitochondria. The fluke mitochondria exhibited cyanide- and antimycin A-sensitive succinate oxidase activity at a rate of 16.8 nmol O2 min-1 mg-1 protein. The succinate oxidation was shown to be stimulated by ADP and linked to the formation of membrane potential. The specific activities of oxidoreductases composing the succinate oxidase system, i.e., succinate-ubiquinone and succinate--cytochrome c oxidoreductase (complex II and complex II-III, respectively) and cytochrome c oxidase (complex IV), were compared in mitochondria from adult Paragonimus, bovine heart (an aerobic tissue), and muscle of adult Ascaris suum which possesses an anaerobic respiratory chain. The activity values of complex II-III and complex IV were high, middle, and low for bovine heart, Paragonimus, and A. suum, respectively, whereas the activity of complex II was comparable among the three sources. The cytochrome contents of Paragonimus mitochondria as determined by difference absorption spectrophotometry ranged between those in Ascaris and bovine mitochondria for types c and aa3 cytochromes. Paragonimus mitochondria exhibited a high activity of NADH-fumarate reductase; the specific activity was about 18-fold higher in fluke submitochondria than in bovine heart submitochondria. Quinone analysis by HPLC and mass spectrometry showed that the fluke mitochondria contain both rhodoquinone-10 and ubiquinone-10 at concentrations of 0.572 and 0.321 nmol mg-1 mitochondrial protein, respectively. These data clearly show that mitochondria from adult P. westermani, unlike adult Ascaris mitochondria, possess both cyanide-sensitive succinate oxidase and NADH-fumarate reductase systems, indicating that the fluke mitochondria are facultatively anaerobic.
在分离的线粒体中对成年卫氏并殖吸虫（一种肺吸虫）的呼吸链进行了表征。该吸虫线粒体表现出对氰化物和抗霉素A敏感的琥珀酸氧化酶活性，速率为16.8 nmol O2 min-1 mg-1蛋白质。琥珀酸氧化被证明受ADP刺激，并与膜电位的形成相关。比较了组成琥珀酸氧化酶系统的氧化还原酶的比活性，即琥珀酸-泛醌和琥珀酸-细胞色素c氧化还原酶（分别为复合体II和复合体II-III）以及细胞色素c氧化酶（复合体IV），这些酶来自成年卫氏并殖吸虫、牛心脏（一种需氧组织）和成年猪蛔虫的肌肉，猪蛔虫具有厌氧呼吸链。复合体II-III和复合体IV的活性值在牛心脏、卫氏并殖吸虫和猪蛔虫中分别为高、中、低水平，而复合体II的活性在这三种来源中相当。通过差示吸收分光光度法测定，卫氏并殖吸虫线粒体的细胞色素含量在蛔虫和牛线粒体的c型和aa3型细胞色素含量之间。卫氏并殖吸虫线粒体表现出较高的NADH-延胡索酸还原酶活性；吸虫亚线粒体中的比活性比牛心脏亚线粒体中的高约18倍。通过高效液相色谱和质谱对醌进行分析表明，吸虫线粒体中分别含有浓度为0.572和0.321 nmol mg-1线粒体蛋白的玫红醌-10和泛醌-10。这些数据清楚地表明，成年卫氏并殖吸虫的线粒体与成年蛔虫的线粒体不同，同时拥有对氰化物敏感的琥珀酸氧化酶和NADH-延胡索酸还原酶系统，这表明吸虫线粒体是兼性厌氧的。
