Molecular properties of cytochrome c oxidase in Ascaris respiratory chain and its response to oxygen tension

蛔虫呼吸链细胞色素c氧化酶的分子特性及其对氧张力的响应

基本信息

批准号：
10670239
负责人：
TAKAMIYA Shinzaburo
金额：
$ 2.11万
依托单位：
Juntendo University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670239/
关键词：
Ascaris suum respiratory chain cytochrome c oxidase response to oxygen tension C. elegans Rhodoquinone fumarate reductase complex II ミトコンドリア

项目摘要

1.Achievement in l998: The respiratory chain of Caenorhabditis elegans was characterized in mitochondria isolated from aerobically grown nematodes. Nematode mitochondria contain ubiquinone-9 as a major component and rhodoquinone-9 as a minor component. The ratio of ubiquinone-9/rhodoquinone-9 is higher in C. elegans mitochondria than in mitochondria from second-stage larvae of Ascaris suum, the free-living stage of porcine gut-dwelling nematode. The individual oxidoreductase activities comprising succinate-oxidase and the amount of substrate-reducible cytochromes are comparable to those of mitochondria from second-stage larvae of A. suum. The specific activity of fumarate reductase is lower in C. elegans mitochondria than in mitochondria from second-stage larvae of A. suum, but still higher than in mammalian mitochondria. These results indicate that the free-living nematode C. elegans is capable of synthesizing rhodoquinone, as distinguished from aerobic mammalian species, although its mitochondria appear more aerobic than A. suum larval mitochondria.2. Achievement in 1999: The Ip subunit of Ascaris suum larval complex II was characterized because Northern hybridization showed that the adult Ip also is expressed in the larvae. The Ip of larval complex II was recognized by the antibody against adult Ip, and was indistinguishable from the adult Ip by peptide mapping. The N-terminal 42 amino acid sequence of Ip in the larval complex II purified by DEAE-cellulofine column chromatography was identical to that of the mature form of the adult Ip. Furthermore, the amino acid composition of larval Ip determined by micro-analysis on a PVDF membrane is almost the same as that of adult Ip. These results suggest that the two different stage-specific forms of the A. suum complex II share a common Ip subunit, even though the adult enzyme functions as a fumarate reductase, while larval enzyme acts as a succinate dehydrogenase.

1. L998的成就：秀丽隐杆线虫的呼吸链在从有氧生长线虫中分离出来的线粒体中。线虫线粒体含有泛素酮-9作为主要成分，若迪喹酮-9作为次要组成部分。秀丽隐杆线虫线粒体的泛素酮-9/Rhodoquinone-9的比率高于腹腔肠肠孔的自由生活阶段的第二阶段幼虫的线粒体。包含琥珀酸酯氧化酶的单个氧化还原酶活性和底物可还原的细胞色素量可与A. suum二级幼虫的线粒体相媲美。秀丽隐杆线虫线粒体中富马酸酸酯还原酶的特异活性比在A. suum的二阶段幼虫中低的线粒体中低，但仍然高于哺乳动物线粒体。这些结果表明，自由生命的线虫秀丽隐杆线虫能够合成若迪喹酮，因为它与有氧哺乳动物物种不同，尽管其线粒体似乎比A. suum suum幼虫线粒体更有氧。2。 1999年的成就：表征了Ascaris suum幼虫复合物II的IP亚基，因为北部杂交表明成年IP在幼虫中也表达。幼虫复合物II的IP通过对成年IP的抗体识别，并且与肽映射与成年IP无法区分。幼虫复合物II中IP的N末端42氨基酸序列由Deae-Cellulofine柱色谱纯化，与成年IP成熟形式的N末端II相同。此外，通过在PVDF膜上微分析确定的幼虫IP的氨基酸组成几乎与成年IP相同。这些结果表明，即使成年酶起富马酸酯还原酶的作用，但两种不同的阶段特异性形式具有共同的IP亚基，而幼虫酶则作为琥珀酸脱氢酶。