Imagawa T, Kasai S, Matsui K, Nakamura T
J Biochem. 1982 Oct;92(4):1109-21. doi: 10.1093/oxfordjournals.jbchem.a134027.
A new peroxide compound (ML-X) was isolated from an autoxidation product of methyl linoleate and was determined as methyl 9-hydroperoxy-12, 13-epoxy-10-octadecenoate. This compound inhibited state 3 respiration of rat heart- and liver mitochondria when glutamate and malate were used as substrates, but not when the substrate was succinate. State 4 respiration of mitochondria was not affected when glutamate-malate was used as the substrate, but it was stimulated when the substrate was succinate. ML-X inhibited oxidative phosphorylation of the mitochondria and abolished the membrane potential formed by respiration or by added ATP. NADH oxidase activity of submitochondrial particles was inhibited by ML-X but succinate oxidase activity was not inhibited. NADH-acceptor reductase activities of submitochondrial particles were inhibited by ML-X to the same extents as by rotenone. These findings show that ML-X has dual effects on mitochondrial respiration as (1) an inhibitor of NADH dehydrogenase complex and (2) an uncoupler. Neither methyl linoleate monohydroperoxide nor methyl epoxy stearate has such effects. ML-X is a new type of inhibitor-uncoupler of mitochondrial respiration in which hydroperoxy- and epoxy groups co-operate.
从亚油酸甲酯的自氧化产物中分离出一种新的过氧化物化合物（ML-X），并确定其为9-氢过氧-12,13-环氧-10-十八碳烯酸甲酯。当以谷氨酸和苹果酸为底物时，该化合物抑制大鼠心脏和肝脏线粒体的状态3呼吸，但当底物为琥珀酸时则不抑制。当以谷氨酸-苹果酸为底物时，线粒体的状态4呼吸不受影响，但当底物为琥珀酸时则受到刺激。ML-X抑制线粒体的氧化磷酸化，并消除由呼吸或添加ATP形成的膜电位。ML-X抑制亚线粒体颗粒的NADH氧化酶活性，但不抑制琥珀酸氧化酶活性。ML-X对亚线粒体颗粒的NADH-受体还原酶活性的抑制程度与鱼藤酮相同。这些发现表明，ML-X对线粒体呼吸具有双重作用：（1）作为NADH脱氢酶复合物的抑制剂；（2）作为解偶联剂。亚油酸甲酯单氢过氧化物和环氧硬脂酸甲酯均无此作用。ML-X是一种新型的线粒体呼吸抑制剂-解偶联剂，其中氢过氧基团和环氧基团协同作用。
