活点结构和塑酸的电子转移反应性
Katsuko Sato1, Takamitsu Kohzuma, Christopher Dennison
1Department of Chemistry, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, UK.
Journal of the American Chemical Society
|February 20, 2003
概括
铜塑素 (PCu) 的活性部位结构
科学领域:
- 生物化学 生物化学
- 生物物理学的生物物理.
- 进化生物学 进化生物学
背景情况:
- 铜塑素 (PCu) 是氧化还原金属蛋白,对各种生物体的电子转移至关重要.
- 在整个进化过程中,PCu的活点结构一直保持不变.
- 电子转移 (ET) 反应性受蛋白质结构和表面电荷分布的影响.
研究的目的:
- 调查来自不同进化起源的PCu的活点结构和电子自我交换 (ESE) 反应性.
- 为了将结构特征,特别是表面酸性残留与ET率相关联.
- 了解PCu结构的进化保存及其对功能的影响.
主要方法:
- 参磁性 (1) H NMR光谱学被用于分析PCu's.的活性部位结构.
- 用电子自我交换 (ESE) 反应来测量电子转移速率.
- 在不同的离子强度和pH值进行了研究,以评估充电残留和质子化的影响.
主要成果:
- 在植物,藻类和蓝菌中,PCu活点结构和旋转密度分布高度保留.
- ESE速率常数有显著的变化,与酸性表面残留物的存在和分布相关.
- 较高的离子强度和清除酸性残留物增加了ESE速率,这表明具有相似的内在ET能力.
- 当酸性补丁的影响最小化时,PCu (I) 中His87的质子化会降低ESE率.
结论:
- 维护PCu的活点结构有助于PCu在不同物种的电子转移中发挥作用.
- 表面电荷分布,特别是酸性残留物,在调节ET反应性方面发挥着关键作用.
- PCu的进化轨迹保持了结构完整性,同时调整了表面特征以微调ET效率.
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