在混合金属血红蛋白杂交体内前向/反向电子转移中的平衡/不平衡初始配置
Ami D Patel1, Judith M Nocek, Brian M Hoffman
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA.
Journal of the American Chemical Society
|December 1, 2005
概括
蛋白质复合体中的电子转移 (ET) 取决于形状. 这项研究表明,粘度对前进和后退ET反应的影响不同,随着粘度的增加,后退率会增加.
科学领域:
- 生物化学 生物化学
- 物理化学 物理化学
- 蛋白质动力学 蛋白质动力学
背景情况:
- 蛋白质-蛋白质电子转移 (ET) 涉及各种配置的复合体.
- 电荷分离的中间体存在于非平衡状态,具有最大的ET矩阵元素.
研究的目的:
- 调查蛋白质光循环中前后ET速率常数的差异粘度依赖.
- 测试构造变化影响ET反应动态的假设.
主要方法:
- 在pH 7.0下研究了一种[alpha2(Zn),beta2(Fe3+N3-) ]混合金属血红蛋白混合体的光循环.
- 分析了前向 (kf) 和后向 (kb) 电子转移速率常数的粘度依赖.
主要成果:
- 前期ET速率常数 (kf) 随着粘度的增加而下降.
- 逆向ET速率常数 (kb) 随着粘度的增加而大大增加,与简单的扩散控制的预期相反.
结论:
- 蛋白质构造显著影响电子转移效率.
- 粘度对前置和后置ET有不同的影响,这表明构造性门控制着光周期.
- 这些发现支持一个模型,其中结构动力学,而不仅仅是扩散,控制电子传输速率.
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