The submitochondrial localization of monoamine oxidase. An enzymatic marker for the outer membrane of rat liver mitochondria.
The submitochondrial localization of monoamine oxidase. An enzymatic marker for the outer membrane of rat liver mitochondria.
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DOI：
10.1083/jcb.32.3.719
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发表时间：
1967-03
期刊：
影响因子：
--
通讯作者：
Greenawalt JW
中科院分区：
文献类型：
--
作者：
Schnaitman C;Erwin VG;Greenawalt JW
大鼠肝线粒体的受控渗透裂解（水洗）导致主要来自线粒体外膜的小泡和含有来自内膜的少量嵴的较大体的混合群体。这些元素已被分离Ficoll和蔗糖梯度。小泡富含单胺氧化酶，大泡富含细胞色素氧化酶。还可以通过在等渗介质中用毛地黄皂苷处理线粒体并通过差速离心对处理后的线粒体进行分级来实现内膜和外膜的分离。低浓度毛地黄皂苷处理释放单胺氧化酶活性从低速线粒体颗粒，和这种释放的酶活性与损失的外膜，如在电子显微镜中看到的。低速离心的线粒体颗粒含有完整线粒体的大部分细胞色素氧化酶和苹果酸脱氢酶活性，而单胺氧化酶活性可以通过高速离心的低速上清液以小泡的形式恢复。结果表明，单胺氧化酶只存在于线粒体外膜，细胞色素氧化酶只存在于内膜。毛地黄皂苷处理释放更多的单胺氧化酶比细胞色素氧化酶从声波粒子，从而表明毛地黄皂苷优先降解外线粒体膜。
Controlled osmotic lysis (water-washing) of rat liver mitochondria results in a mixed population of small vesicles derived mainly from the outer mitochondrial membrane and of larger bodies containing a few cristae derived from the inner membrane. These elements have been separated on Ficoll and sucrose gradients. The small vesicles were rich in monoamine oxidase, and the large bodies were rich in cytochrome oxidase. Separation of the inner and outer membranes has also been accomplished by treating mitochondria with digitonin in an isotonic medium and fractionating the treated mitochondria by differential centrifugation. Treatment with low digitonin concentrations released monoamine oxidase activity from low speed mitochondrial pellets, and this release of enzymatic activity was correlated with the loss of the outer membrane as seen in the electron microscope. The low speed mitochondrial pellet contained most of the cytochrome oxidase and malate dehydrogenase activities of the intact mitochondria, while the monoamine oxidase activity could be recovered in the form of small vesicles by high speed centrifugation of the low speed supernatant. The results indicate that monoamine oxidase is found only in the outer mitochondrial membrane and that cytochrome oxidase is found only in the inner membrane. Digitonin treatment released more monoamine oxidase than cytochrome oxidase from sonic particles, thus indicating that digitonin preferentially degrades the outer mitochondrial membrane.