从共振拉曼光谱学和DFT建模中对Fe(III) 血红蛋白中NO结合的新发现
Alexandra V Soldatova1, Mohammed Ibrahim, John S Olson
1Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, USA.
Journal of the American Chemical Society
|March 12, 2010
概括
共振拉曼光谱揭示了遥远的血口袋极性如何影响肌球蛋白中的铁-酸盐 (Fe-NO) 键. 变化的极性影响NO键强度,影响生物氧化 (NO) 过程.
科学领域:
- 生物物理化学 生物物理化学
- 频谱学是一种光谱学.
- 计算化学计算化学
背景情况:
- 研究了具有修改远端血口袋的髓蛋白变体.
- 铁-酸盐 (Fe-NO) 添加物在生物氧化 (NO) 途径中至关重要.
- 了解Fe-NO相互作用可以了解NO代谢.
研究的目的:
- 为了研究血口袋极性和Fe-NO键特性之间的关系.
- 探索远端胺和血替代剂在Fe-NO延伸频率上的作用.
- 阐明影响Fe-NO曲的机制及其与键强度的相关性.
主要方法:
- 可见和紫外线共振雷曼 (RR) 谱学对肌球蛋白变异的分析.
- 密度函数理论 (DFT) 对Fe (III) -NO adducts的建模.
- 对Fe (III) -NO (nu ((FeN)) 和N-O (nu ((NO)) 键的拉伸频率的分析.
主要成果:
- 观察到nu(FeN) 和nu(NO) 之间存在负相关性,这表明存在背链.
- 远端胺的损失改变了相关性,加强了N-O键.
- 提取电子的血替代剂诱导了Fe-N-O曲,导致了正相关性.
结论:
- 黑米口袋极性和易斯基可访问性显著影响Fe-NO键动态.
- RR光谱和DFT建模有效地报告了海姆口袋环境.
- 这些发现对理解生物系统中氧化 (NO) 结合,化和减少有意义.
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