Iwase H, Takatori T, Niijima H, Nagao M, Amano T, Iwadate K, Matsuda Y, Nakajima M, Kobayashi M
Department of Forensic Medicine, Faculty of Medicine, University of Tokyo, Japan.
Biochim Biophys Acta. 1997 Mar 10;1345(1):27-34. doi: 10.1016/s0005-2760(96)00155-5.
Myoglobin (Mb) and cytochrome c (Cyt c) are known to promote lipid peroxidation when mixed with certain types of phospholipids. In the presence of phospholipids such as cardiolipin (CL), ferrous Mb and Cyt c were converted to ferric hemoproteins, and autoxidation of the phospholipids and the oxidation of free linoleic acid (LA) added to the reaction mixture were observed. When the reaction mixture comprising 0.01 mM Cyt c, 0.2 mM CL and 0.1 mM LA was incubated, 92.7% of LA was consumed, and the LA products included 2.49 microM 9,10-epoxy-12-octadecenoic acid (leukotoxin) and its isomer which are potent inhibitors of mitochondrial respiration and have toxic effects on cardiac function. Hemoglobin (Hb) could promote almost no lipid peroxidation in the presence of any kinds of phospholipids. The experiments using some scavengers of active oxygen species revealed that tocopherol and ascorbic acid could strongly reduced LA oxidation caused by Cyt c or Mb. As LTx production was also observed when LA was mixed with Fe2+, LTx may be a common product where non-enzymatic lipid peroxidation occurs.
已知肌红蛋白（Mb）和细胞色素c（Cyt c）与某些类型的磷脂混合时会促进脂质过氧化。在诸如心磷脂（CL）等磷脂存在的情况下，亚铁型Mb和Cyt c会转化为高铁血红素蛋白，并且观察到磷脂的自动氧化以及添加到反应混合物中的游离亚油酸（LA）的氧化。当包含0.01 mM Cyt c、0.2 mM CL和0.1 mM LA的反应混合物孵育时，92.7%的LA被消耗，并且LA产物包括2.49 microM 9,10-环氧-12-十八碳烯酸（白细胞毒素）及其异构体，它们是线粒体呼吸的有效抑制剂，对心脏功能有毒性作用。在任何种类的磷脂存在下，血红蛋白（Hb）几乎不会促进脂质过氧化。使用一些活性氧清除剂的实验表明，生育酚和抗坏血酸可以强烈降低由Cyt c或Mb引起的LA氧化。由于当LA与Fe2+混合时也观察到LTx的产生，LTx可能是发生非酶促脂质过氧化的常见产物。
