由和硫离子介导的周期性跨膜电荷传输
1Contribution from the Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA.
Journal of the American Chemical Society
|July 27, 2001
概括
酸离子通过形成穿透脂质囊泡的中性基来促进跨膜电子转移. 这种氧化还原循环机制能够有效地减少封装的复合物,并保持电子中立性.
科学领域:
- 摄影化学的使用.
- 超分子化学 超分子化学
- 膜运输 运输 膜运输
背景情况:
- 兴奋的三重金属氨酸是各种氧化还原过程中关键的光活性物种.
- 和硫离子是已知的电子受体,具有可调节的氧化还原潜力.
- 脂质囊泡作为细胞膜的模型系统,使得运输现象的研究.
研究的目的:
- 为了研究光激发的色素和/离子之间的相互作用.
- 阐明由基调解的跨膜电子转移机制.
- 确定pyrylium物种的膜透性及其在氧化还原循环中的作用.
主要方法:
- 暂时吸收光谱检测激发状态火和激素形成.
- 停止流动动力学来测量火速常数及其对氧化还原潜力的依赖.
- 基于囊泡的测试来量化跨膜减少,并确定透系数.
主要成果:
- 和硫离子以氧化方式灭激发的三重色素,形成中性基和色素离子.
- 火率与的降解潜力相关,表明热力学驱动的过程.
- 只有中性基具有显著的膜透性,有效地减少具有高量子产量的封装复合物.
结论:
- 基作为高效的,膜透的电子载体,用于跨膜氧化还原反应.
- 一个拟议的循环涉及酸的水解和中性二基的扩散,以再生载体.
- 离子作为氧化物和电子的循环反载体,在膜上保持电子中立性.
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