Mitochondrial recycling of ascorbic acid from dehydroascorbic acid: dependence on the electron transport chain
Mitochondrial recycling of ascorbic acid from dehydroascorbic acid: dependence on the electron transport chain
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DOI：
10.1016/s0003-9861(02)00205-9
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发表时间：
2002-07-01
影响因子：
3.9
通讯作者：
May, JM
中科院分区：
文献类型：
--
作者：
Li, X;Cobb, CE;May, JM
线粒体可以从其氧化形式中再生抗坏血酸，这可能有助于维持线粒体和细胞质中的维生素。在这项工作中，我们试图确定线粒体从脱氢抗坏血酸中回收抗坏血酸的位置和机制。大鼠骨骼肌线粒体与500muM脱氢抗坏血酸和能量底物在37℃下孵育3h后，其抗坏血酸浓度维持在无底物条件下的两倍以上。琥珀酸依赖的线粒体脱氢抗坏血酸还原被线粒体复合物II和III的抑制剂阻断。细胞色素c和线粒体外膜都不是产生这种效果所必需的。抗坏血酸自由基在脱氢抗坏血酸处理期间由线粒体产生，并被铁氰化物清除，铁氰化物不穿透线粒体内膜。总之，这些结果表明，脱氢抗坏血酸的能量底物依赖性抗坏血酸回收涉及线粒体复合体III的外部暴露部分。(C) 2002 Elsevier Science （USA）。版权所有。
Mitochondria can regenerate ascorbic acid from its oxidized forms, which may help to maintain the vitamin both in mitochondria and in the cytoplasm, In this work, we sought to determine the site and mechanism of mitochondrial ascorbate recycling from dehydroascorbic acid. Rat skeletal muscle mitochondria incubated for 3h at 37degreesC with 500muM dehydroascorbic acid and energy substrates maintained ascorbate concentrations more than twice those observed in the absence of substrate. Succinate-dependent mitochondrial reduction of dehydroascorbic acid was blocked by inhibitors of mitochondrial Complexes II and III. Neither cytochrome c nor the outer mitochondrial membrane were necessary for the effect. The ascorbate radical was generated by mitochondria during treatment with dehydroascorbic acid and was abolished by ferricyanide, which does not penetrate the mitochondrial inner membrane. Together, these results show that energy substrate-dependent ascorbate recycling from dehydroascorbic acid involves an externally exposed portion of mitochondrial complex III. (C) 2002 Elsevier Science (USA). All rights reserved.