甲基辅酶m редукта酶活性位点中的化复合物:对催化循环的含义
Jeffrey Harmer1, Cinzia Finazzo, Rafal Piskorski
1Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QR, Oxford, United Kingdom. jeffrey.harmer@chem.ox.ac.uk
Journal of the American Chemical Society
|July 26, 2008
概括
甲产生的古老物种.
科学领域:
- 生物化学 生物化学
- 微生物学 微生物学
- 频谱学是一种光谱学.
背景情况:
- 甲原菌从C1基质或酸盐中产生甲.
- 甲基共酶M减少酶 (MCR) 是甲基生成的关键,利用色素 F430.0.
- 在这些微生物中,MCR的活性部位和催化机制对能量产生至关重要.
研究的目的:
- 为了研究MCR偏磁红2状态的协调连接体.
- 使用先进的光谱技术阐明MCR red2a的结构.
- 了解化复合体在甲基生成中的作用.
主要方法:
- 电子磁共振 (EPR) 谱学,包括连续波和脉冲方法.
- 使用特定基质和抑制剂 (HS-CoM,HS-CoB,CH3-S-CoB) 的酶试验.
- 对偏磁MCR状态 (红1和红2) 的分析.
主要成果:
- 该MCR red2a状态显示出显著的质子高精度相互作用 (A((1) H) = [-43,-42,-5] MHz).
- 这种相互作用表明Ni(III) F430化物复合物的形成通过氧化添加到Ni(I).
- 这项研究描述了MCR在催化过程中的活性部位中的协调配体.
结论:
- 在MCR中确定了一个化复合物,对甲激活具有潜在的关键.
- 这一发现为前进 (甲生成) 和反向 (无氧甲氧化) 途径的机制提供了洞察力.
- 这项研究推动了我们对MCR在古人类新陈代谢中的酶功能的理解.
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