超氧化物脱酶的光谱和计算研究:电子结构对酶功能的贡献
Adam T Fiedler1, Peter A Bryngelson, Michael J Maroney
1University of Wisconsin-Madison, Department of Chemistry, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|April 14, 2005
概括
含超氧化物脱酶 (NiSOD) 酶可以排毒有害的超氧化基. 这项研究揭示了NiSOD中强大的Ni-S结合,对于其功能和有氧生物中的氧化还原潜力的调整至关重要.
科学领域:
- 生物化学 生物化学
- 生物有机化学 生物有机化学
- 频谱学是一种光谱学.
背景情况:
- 含超氧化物脱酶 (NiSOD) 是最近发现的一种金属酶.
- 尼索德在有氧生物中排毒超氧化基,在细胞防御中发挥重要作用.
研究的目的:
- 为了研究 NiSOD 活性位点在氧化 (NiSOD ((ox)) 和减少 (NiSOD ((red)) 状态中的电子结构.
- 阐明结合相互作用及其对NiSOD功能和氧化还原潜力的影响.
主要方法:
- 使用了光谱技术的组合 (包括共振拉曼光谱).
- 采用电子结构计算的计算方法.
- 与实验数据对比的验证计算结果.
主要成果:
- 确定了NiSOD中的Ni和赤道S/N配体之间的强西格玛结合相互作用,与近紫外线电荷转移过渡相关.
- 通过共振拉曼光谱学观察到Ni-S(Cys) 在NiSOD(ox) 中在349和365厘米的拉伸模式.
- 在NiSOD中具有特征的高金属联体键共价性和Ni-S/N pi相互作用,对于调整Ni2+) 氧化还原潜力至关重要.
结论:
- 尼索德的电子结构是其超氧化物排毒功能的关键.
- 阳离子N-供体连接体对于活性部位的基于金属的氧化是必不可少的.
- 与合成复合物的比较凸显了NiSOD中独特的Ni-S(Cys) 结合.
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