Purification and characterization of the cytochrome c oxidase from Rhodopseudomonas sphaeroides.
Purification and characterization of the cytochrome c oxidase from Rhodopseudomonas sphaeroides.
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球形红假单胞菌细胞色素 c 氧化酶的纯化和表征。
DOI：
10.1111/j.1432-1033.1982.tb06667.x
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Ludwig,B
中科院分区：
文献类型：
--
作者：
Gennis,RB;Casey,RP;Azzi,A;Ludwig,B
当在黑暗中有氧生长时，球形红假单胞菌会形成类似于线粒体的呼吸链，并且光合作用装置受到抑制。来自 Rps 的 aa3 型细胞色素 c 氧化酶。球状蛋白已在 Triton X-100 中通过亲和层析（使用与酵母细胞色素偶联的 Sepharose 4B）进行纯化。该氧化酶含有 14 nmol 血红素 a/mg 蛋白质，由相对分子质量分别为 45000、37000 和 35000 的三个多肽亚基组成。该酶在去垢剂存在下具有高活性，使用酵母或马心细胞色素c.TheRps 时，最大速度为 300s−1/mol 氧化酶。球状氧化酶与针对脱氮副球菌和酿酒酵母氧化酶的抗体发生交叉反应。 P 的情况表明了特别密切的关系。脱氮菌。 TheRps。球状氧化酶已被掺入磷脂囊泡中。这些囊泡中产生的氧化酶表现出高酶活性和 5 的呼吸控制比。使用这些囊泡，没有观察到伴随细胞色素 c 氧化的质子挤出的证据。数据表明，Rps。球状氧化酶不发挥质子泵的作用。
When grown aerobically in the dark,Rhodopseudomonas sphaeroidesdevelops a respiratory chain similar to that in mitochondria and the photosynthetic apparatus is suppressed. The aa3‐type cytochrome c oxidase fromRps. sphaeroideshas been purified in Triton X‐100 by affinity chromatography with Sepharose 4B coupled to yeast cytochromec. The oxidase contains 14 nmol heme a/mg protein and is composed of three polypeptide subunits with relative molecular masses of 45000, 37000 and 35000. The enzyme is highly active in the presence of detergents, with a maximal velocity of 300s−1/mol oxidase using either yeast or horse‐heart cytochromec.TheRps. sphaeroides oxidaseis cross‐reactive with antibodies directed against the oxidases fromParacoccus denitrificansandSaccharomyces cerevisiae. A particularly close relationship is indicated in the case ofP. denitrificans. TheRps. sphaeroidesoxidase has been incorporated into phospholipid vesicles. The resulting oxidase in these vesicles demonstrates high enzymatic activity and a respiratory control ratio of 5. Using these vesicles, no evidence for proton extrusion accompanying cytochrome c oxidation was observed. The data suggest that theRps. sphaeroides oxidasedoes not function as a proton pump.