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一系列Fe(II) - thiolate模型复合物的合成,结构确定和光谱/计算表征:对超氧化氧化酶中Fe-S键的含义
Adam T Fiedler1, Heather L Halfen, Jason A Halfen
1University of Wisconsin-Eau Claire, Department of Chemistry, 105 Garfield Avenue, Eau Claire, WI 54702, USA.
Journal of the American Chemical Society
|February 11, 2005
概括
研究人员开发了合成铁二硫酸盐复合体,以模拟超氧化减少酶 (SOR). 复合体3紧密模仿了减少的SOR活性位点的电子结构,揭示了铁硫结合的洞察力.
科学领域:
- 生物有机化学 生物有机化学
- 酶活性部位仿真是酶活性部位的仿真.
- 协调化学 协调化学
背景情况:
- 超氧化减少酶 (SORs) 是一种酶,可以在无氧生物中排毒超氧化物.
- 减少的SORs的活性部位包含一个由和硫连接体协调的方形金字塔形Fe (II) 中心.
- 了解这些活性位点的电子结构对于酶功能至关重要.
研究的目的:
- 合成和表征新型Fe (II) - 硫酸盐复合物,作为减少SOR活性位点的结构和电子模型.
- 为了研究 Fe(II) -S 结合在带有轴性硫酸盐结合的复合体中的性质.
- 阐明这些模型复合体的电子结构和光谱特性,并将其与原生酶进行比较.
主要方法:
- 综合合成,光谱 (UV-Vis,MCD,VTVH-MCD) 和计算 (DFT,INDO/S-CI) 的方法.
- 用X射线结晶学测定Fe (II) - 硫酸盐复合物的结构.
- 合成复合物的电化学表征.
主要成果:
- 合成和表征Fe (II) - 硫酸盐复合物2和3,其中包括一个N (II) -4) S供体集,以及正方形金字塔和三角形双金字塔之间的中间几何结构.
- 详细的光谱和计算分析提供了关于Fe (II) -S电荷转移过渡和结合的见解.
- 复合体3的吸收光谱与减少的SOR酶 (SOR 红色) 非常相似,表明了活性位点电子结构的准确模仿,特别是共价Fe-S pi-和西格玛相互作用.
结论:
- 复合物3及其结合的基硫酸盐有效地模拟了SOR (红色) 活性位点的电子结构,包括囊类残留物的方向.
- 这项研究为生物相关系统中Fe(II) -S结合的性质提供了重要的见解.
- 这些发现对理解超氧化还原酶的电子结构和反应性有意义.
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