Skeletal muscle sarcoplasmic reticulum contains a NADH-dependent oxidase that generates superoxide.
Skeletal muscle sarcoplasmic reticulum contains a NADH-dependent oxidase that generates superoxide.
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骨骼肌肌浆网含有 NADH 依赖性氧化酶，可产生超氧化物。
DOI：
10.1152/ajpcell.00034.2002
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Abramson,JonathanJ
中科院分区：
文献类型：
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作者：
Xia,Ruohong;Webb,JasonA;Gnall,LisaLM;Cutler,Kerry;Abramson,JonathanJ
骨骼肌肌浆网(SR)被证明含有一种NADH依赖的氧化酶(NOX)，它能还原分子氧生成超氧化物。它的活性与钙释放机制的激活有关，高亲和力兰尼定结合率的刺激证明了这一点。NOx的活性，与超氧化物的产生相结合，不是来自线粒体，而是起源于SR。SR制剂还含有显著的NADH氧化酶活性，它与超氧化物的产生没有偶联，似乎起源于线粒体。这种线粒体成分优先与SR的末端脑池区域相关。其活性可被二苯基碘(10μM)、抗霉素A(200 NM)和鱼藤酮(40 NM)抑制，但不与超氧化物的产生或兰尼定受体的刺激相偶联。在SR中，每毫克蛋白质产生超氧化物的速率高于线粒体。这种氮氧化物可能是肌肉中氧化应激的一个主要来源。
Skeletal muscle sarcoplasmic reticulum (SR) is shown to contain an NADH-dependent oxidase (NOX) that reduces molecular oxygen to generate superoxide. Its activity is coupled to an activation of the Ca2+release mechanism, as evident by stimulation in the rate of high-affinity ryanodine binding. NOX activity, coupled to the production of superoxide, is not derived from the mitochondria but is SR in origin. The SR preparation also contains a significant NADH oxidase activity, which is not coupled to the production of superoxide and appears to be mitochondrial in origin. This mitochondrial component is preferentially associated with the terminal cisternae region of the SR. Its activity is inhibited by diphenylene iodonium (10 μM), antimycin A (200 nM), and rotenone (40 nM) but is not coupled to the generation of superoxide or the stimulation of the ryanodine receptor. The rate of superoxide production per milligram of protein is larger in SR than in mitochondria. This NOX may be a major source of oxidative stress in muscle.