在氧化酶模型中的cis-MoOS单元的电子结构描述
Christian J Doonan1, Nick D Rubie, Katrina Peariso
1The Department of Chemistry and Biological Chemistry, The University of New Mexico, MSC03 20601 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA.
Journal of the American Chemical Society
|December 8, 2007
概括
氧化酶使用独特的cis-MoOS位点进行氧气转移. 新的模型揭示了一个非局部化的氧化还原轨道,影响Mo-S结合和基质氧化酶机制.
科学领域:
- 生物有机化学 生物有机化学
- 酶的机制 酶的机制
- 有机金属化学 有机金属化学
背景情况:
- 氧化酶是催化氧化反应的关键酶.
- 他们独特地使用水作为产品合并的氧气来源.
- 了解他们活跃网站的电子结构是他们功能的关键.
研究的目的:
- 在新的模型化合物中研究cis-molybdenum-oxo-sulfido (MoOS) 单元的电子结构.
- 阐明这些电子结构在氧化酶机制中的作用.
- 为了将光谱和计算数据与酶功能相关联.
主要方法:
- 合成了新的氧化酶模型化合物:CoCp2[TpiPrMoVOS(OPh) ]和TpiPrMoVIOS(OPh).
- 光谱分析包括SK边缘X射线吸收和振动光谱.
- 详细的粘合和电子结构计算.
主要成果:
- 鉴定一个高度脱位的Mo=S pi* LUMO氧化还原轨道,具有显著的硫化连接体特性.
- 通过振动光谱学量化Mo-Sulfido键的顺序变化与氧化还原状态.
- 证明一个有氧化还原活性分子轨道显著影响MoOS结合和硫化联体特性.
结论:
- cis-MoOS位点的电子结构具有氧化还原活性,并控制酶机制.
- 轨道控制由MoOS站点独特的电子驱动,控制基质氧化.
- 氧化酶部位可能会使基质两极分化,并充当电子沉降器.
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