在红色和蓝色Cu中对比二次协调球体对旋转密度分布的影响,而蓝色Cu则是蓝色
Casey Van Stappen1, Edward Reijerse2, Sonia Chabbra2
1Department of Chemistry, University of Texas at Austin, 105 E 24th St., Austin, TX, 78712, USA.
概括
金属蛋白使用二次协调球体效应来调整金属活性位点. 这项研究比较了这些对蓝色和红色铜中心的影响,揭示了类似的静电冲击,但在H结合中断时发生了相反的变化.
科学领域:
- 生物化学和生物物理学
- 生物有机化学 生物有机化学
- 蛋白质的电子转移是蛋白质的电子转移.
背景情况:
- 金属蛋白利用初级和二级协调球 (PCS和SCS) 效应来调节金属活性部位的电子特性,用于氧化还原化学.
- 氧化还原活性分子轨道 (RAMOs) 的空间分布,受到SCS效应的影响,决定了金属蛋白的氧化还原行为.
- 对不同空间分布的RAMOs上SCS影响的实验调查仍然具有挑战性.
研究的目的:
- 为了比较和对比相同的SCS修改对同一蛋白质支架内的蓝色和红色铜中心电子和几何结构的影响.
- 调查SCS修改如何差异影响蓝色与红色铜青的电子分布和电子结构.
主要方法:
- 利用1H和14N电子核双共振 (ENDOR) 光谱来检查红色CuAz变体中的未配对电子分布.
- 将ENDOR数据与先前的研究和密度函数理论 (DFT) 计算结合起来进行综合分析.
- 对蓝铜青素 (Blue CuAz) 和其红铜变体 (Red CuAz) 的SCS效应进行比较,具有明显的RAMO特征 (Cu-Sπ与Cu-Sσ).
主要成果:
- 在铜 (Cu) 和硫 (S) 原子附近引入的二极子时刻的静电效应对红色和蓝色CuAz.Az.产生了类似的自旋密度分布变化.
- F114P突变破坏了与硫的结合,在红色和蓝色CuAz中产生了相反的效应.
- 相反的效应归因于Cys112侧链形状的差异,在没有稳定性SC112H-N骨干相互作用的情况下采用.
结论:
- SCS 修改对具有明显 RAMO 空间分布的铜中心的电子结构产生了相似的 (静电学) 和差异性的 (H 结合破坏) 影响.
- 蛋白质支架的结构适应性在调节SCS效应的影响方面发挥着至关重要的作用,特别是在响应键扰动时.
- 这项比较研究更深入地了解了蛋白质结构,金属中心电子和金属蛋白中的氧化还原功能之间的复杂相互作用.
关键词:
蓝色的蓝色是蓝色的恩多尔 (英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor,英语:Endor.金属蛋白质是一种金属蛋白质.脉冲 EPR 是一个脉冲 EPR.二次协调领域 二次协调领域更多相关视频
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