• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Plant physiology >Inhibition of 2-Oxoglutarate Dehydrogenase in Potato Tuber Suggests the Enzyme Is Limiting for Respiration and Confirms Its Importance in Nitrogen Assimilation
【24h】

Inhibition of 2-Oxoglutarate Dehydrogenase in Potato Tuber Suggests the Enzyme Is Limiting for Respiration and Confirms Its Importance in Nitrogen Assimilation

机译：马铃薯块茎中2-氧戊二酸脱氢酶的抑制表明该酶限制了呼吸作用，并确认了其在氮同化中的重要性。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The 2-oxoglutarate dehydrogenase complex constitutes a mitochondrially localized tricarboxylic acid cycle multienzyme system responsible for the conversion of 2-oxoglutarate to succinyl-coenzyme A concomitant with NAD+ reduction. Although regulatory mechanisms of plant enzyme complexes have been characterized in vitro, little is known concerning their role in plant metabolism in situ. This issue has recently been addressed at the cellular level in nonplant systems via the use of specific phosphonate inhibitors of the enzyme. Here, we describe the application of these inhibitors for the functional analysis of the potato (Solanum tuberosum) tuber 2-oxoglutarate dehydrogenase complex. In vitro experiments revealed that succinyl phosphonate (SP) and a carboxy ethyl ester of SP are slow-binding inhibitors of the 2-oxoglutarate dehydrogenase complex, displaying greater inhibitory effects than a diethyl ester of SP, a phosphono ethyl ester of SP, or a triethyl ester of SP. Incubation of potato tuber slices with the inhibitors revealed that they were adequately taken up by the tissue and produced the anticipated effects on the in situ enzyme activity. In order to assess the metabolic consequences of the 2-oxoglutarate dehydrogenase complex inhibition, we evaluated the levels of a broad range of primary metabolites using an established gas chromatography-mass spectrometry method. We additionally analyzed the rate of respiration in both tuber discs and isolated mitochondria. Finally, we evaluated the metabolic fate of radiolabeled acetate, 2-oxoglutarate or glucose, and C-13-labeled pyruvate and glutamate following incubation of tuber discs in the presence or absence of either SP or the carboxy ethyl ester of SP. The data obtained are discussed in the context of the roles of the 2-oxoglutarate dehydrogenase complex in respiration and carbon-nitrogen interactions.
机译：2-氧戊二酸脱氢酶复合物构成线粒体定位的三羧酸循环多酶系统，该系统负责将2-氧戊二酸转化为琥珀酰辅酶A，并伴随NAD +还原。尽管植物酶复合物的调节机制已在体外进行了表征，但关于它们在原位植物代谢中的作用知之甚少。通过使用该酶的特定膦酸酯抑制剂，最近已经在非植物系统的细胞水平上解决了该问题。在这里，我们描述了这些抑制剂在马铃薯（马铃薯）块茎2-氧戊二酸脱氢酶复合物功能分析中的应用。体外实验表明，琥珀酸膦酸酯（SP）和SP的羧乙基酯是2-氧戊二酸脱氢酶复合物的慢结合抑制剂，与SP的二乙酯，SP的膦酰基乙酯或SP的磷酸乙酯相比，显示出更大的抑制作用。 SP的三乙酯。将马铃薯块茎切片与抑制剂一起孵育表明它们已被组织充分吸收，并且对原位酶活性产生了预期的影响。为了评估2-氧代戊二酸脱氢酶复合物抑制的代谢后果，我们使用已建立的气相色谱-质谱法评估了多种主要代谢物的水平。我们还分析了块茎盘和孤立的线粒体中的呼吸速率。最后，我们在存在或不存在SP或SP的羧乙基酯的情况下孵育块茎盘后，评估了放射性标记的乙酸盐，2-氧代戊二酸或葡萄糖以及C-13标记的丙酮酸和谷氨酸的代谢命运。在2-氧戊二酸脱氢酶复合物在呼吸作用和碳-氮相互作用中的作用中讨论了获得的数据。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
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