在克雷布斯循环中脱离路径,依赖氧气的胺基
René A W Frank1, Christopher W M Kay, Judy Hirst
1Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
Journal of the American Chemical Society
|January 11, 2008
概括
研究人员在克雷布斯循环的关键酶中发现了一种依赖氧的自由基. 在正常酶功能过程中产生的这种基因产生反应性氧物种,可能与神经退行性疾病有关.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 代谢途径 代谢途径
背景情况:
- 硫胺二酸盐 (TDP) 是许多酶在中心代谢中的重要辅助因子.
- 三碳酸 (TCA) 循环是细胞能量生产的基石.
研究的目的:
- 为了研究依赖TDP的埃舍里希亚大肠杆菌2-oxoglutarate脱酶的机制.
- 在有氧条件下在酶循环过程中识别反应性中间体.
主要方法:
- 用大肠杆菌2-oxoglutarate脱酶进行酶活性测定.
- 在液温度下对反应性中间体进行冷捕获.
- 电子偏磁共振 (EPR) 和电子核双共振 (ENDOR) 光谱.
主要成果:
- 检测和描述一种长寿的,依赖氧气的自由基.
- 光谱分析显示,在一个酶胺-硫中间体上,有一种非局部化的pi基.
- 基质在基质周转过程中通过与分子氧的副作用反应产生.
结论:
- 在2-oxoglutarate脱酶中形成了一种新的依赖氧的基质中间体.
- 在有氧条件下,这种离路反应不断产生活性氧物种.
- 激素机制可能导致神经退行性疾病中的代谢功能障碍.
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