长距离电子转移的重组自由能量在一个氨酸结合的四螺旋束蛋白质中
Jochen Blumberger1, Michael L Klein
1Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Journal of the American Chemical Society
|October 19, 2006
概括
通过计算重组自由能来研究设计蛋白质中的电子运输. 溶剂显著影响电子转移,但突变可能会降低能量障碍.
科学领域:
- 生物物理化学 生物物理化学
- 计算生化学计算生化学
- 蛋白质工程是指蛋白质工程.
背景情况:
- 电子运输在生物系统中至关重要.
- 了解设计蛋白质中的电子转移,可以为人工系统提供信息.
- 四螺旋束蛋白质为研究电子转移提供了一个支架.
研究的目的:
- 在设计的四螺旋束蛋白中计算电子转移的重组自由能量.
- 研究溶剂和蛋白质在电子转移中的作用.
- 确定优化电子转移速率的潜在策略.
主要方法:
- 传统的静电能量差距采样20 ns.
- 密度函数理论 (DFT) 用于内部球体重组.
- 对溶剂和蛋白质对外层球体重组的贡献进行分析.
主要成果:
- 计算出了0.90 eV (氧化) 和1.36 eV (自我交换) 的重组自由能量.
- 溶剂是氧化外部球体重组的主要贡献者 (69%).
- 对于自我交换,溶剂 (54%) 和蛋白质 (46%) 的贡献几乎相等.
结论:
- 四螺旋束蛋白质对电场的选效果不如预期.
- 突变特定的谷氨胺残留物可能会减少重组自由能量约0.2 eV.
- 设计的蛋白质支架显示了调整电子转移特性的潜力.
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