...
首页> 外文期刊>The biochemical journal >Free-radical-mediated fragmentation of monoamine oxidase in the mitochondrial membrane Roles for lipid radicals
【24h】

Free-radical-mediated fragmentation of monoamine oxidase in the mitochondrial membrane Roles for lipid radicals

机译:自由基介导的单胺氧化酶在线粒体膜中的破碎对脂质自由基的作用

获取原文

摘要

pA flux of hydroxyl radicals generated by gamma-irradiation can fragment monoamine oxidase in the membrane of submitochondrial particles. This fragmentation can be inhibited by mannitol and in addition is more extensive in monoamine oxidase preparations that have been depleted of lipid. This latter observation is consistent with the higher yields of fragmentation induced by hydroxyl radicals in soluble proteins in the absence of added lipids. In the absence of oxygen, gamma-irradiation of submitochondrial particles leads to cross-linking reactions. A flux of hydroperoxyl radicals also causes fragmentation, whereas one of superoxide is virtually inactive in this respect. The irradiation of submitochondrial particles leads in addition to the accumulation of products of lipid peroxidation. When these irradiated preparations are exposed to ferrous or cupric salts a further fragmentation of monoamine oxidase ensues, especially at acid pH. These transition-metal-catalysed reactions do not occur with irradiated preparations depleted of lipid, and the post-irradiation protein modifications are concomitant with further lipid peroxidation. The data indicate roles for lipid radicals in both fragmentation and cross-linking reactions of proteins in biological membranes. These reactions may have an important bearing on control of protein activity and of protein turnover in membranes./p
机译:γ辐射产生的羟基自由基通量可以使线粒体颗粒膜中的单胺氧化酶断裂。甘露醇可以抑制这种断裂,此外,在脂质已经耗尽的单胺氧化酶制剂中,这种断裂作用更为广泛。后一个观察结果与在不添加脂质的情况下由可溶性蛋白质中的羟基自由基诱导的更高断裂率相符。在没有氧气的情况下,线粒体的γ辐射会导致交联反应。氢过氧自由基的通量也会引起断裂,而超氧化物之一在这方面实际上是无活性的。线粒体颗粒的辐射除了导致脂质过氧化产物的积聚之外,还导致其他问题。当这些辐照的制剂暴露于亚铁盐或铜盐中时,会导致单胺氧化酶进一步碎裂,尤其是在酸性pH下。这些过渡金属催化的反应在脂质减少的辐照制剂中不会发生,并且辐照后的蛋白质修饰会伴随脂质的进一步过氧化。数据表明脂质自由基在生物膜中蛋白质的断裂和交联反应中的作用。这些反应可能对控制蛋白质活性和膜中蛋白质更新有重要影响。

著录项

获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号