Abstract

In the present work, the recorded kinetics of chemiluminescence enhanced by coumarin 334 indicated that the complexes of cytochrome c (Cyt) with anionic lipids (Cyt-AL), such as cardiolipin (CL) and phosphatidic acid (PA), when added to mitochondrial and cytoplasmic membranes, are capable of catalysing reactions of lipid free radical formation. The effect of Cyt-CL complex was studied on mitochondria isolated from the liver of male Wistar rats and male outbred mice, as well as on erythrocytes isolated from the blood of male Wistar rats. It was shown that complex Cyt-PA exerts a peroxidase effect similar to the effect produced by Cyt-CL. Upon exposure to Cyt-CL, the formation of free radicals was more prominent in mitochondrial ghosts (mitochondria subjected to freeze-thawing and washed by several precipitation–resuspension cycles) than in intact mitochondria. This suggests that Cyt-CL does not pass through biological membranes: even if it penetrates into them, it probably gets stuck in the phospholipid bilayer. Thus, the previously discovered cytotoxic effect of Cyt-CL on cancer cells is most likely due to peroxidation of the cytoplasmic membrane, but not of the inner membrane of mitochondria.

中文翻译：

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带有阴离子脂质的细胞色素c配合物的形成动力学及这些配合物催化的脂质自由基生成机理

摘要

在目前的工作中，香豆素334增强的化学发光动力学表明，细胞色素c的复合物（Cyt）与阴离子脂质（Cyt-AL）（例如心磷脂（CL）和磷脂酸（PA））一起添加到线粒体和细胞质膜中时，能够催化脂质自由基形成的反应。研究了Cyt-CL复合物对雄性Wistar大鼠和雄性近交小鼠肝脏分离的线粒体以及雄性Wistar大鼠血液分离的红细胞的作用。结果表明，复合物Cyt-PA发挥了与Cyt-CL相似的过氧化物酶作用。暴露于Cyt-CL后，与完整的线粒体相比，线粒体鬼影（经历冻融并经过多个沉淀-重悬浮循环洗涤的线粒体）中自由基的形成更为明显。这表明Cyt-CL不会穿过生物膜：即使它渗透到生物膜中，它可能卡在磷脂双层中。因此，以前发现的Cyt-CL对癌细胞的细胞毒作用最可能是由于细胞质膜的过氧化作用，而不是线粒体内膜的过氧化作用。