Dynamics of photoelectric conversion in biological system as studied by high time resolution and high frequency EPR

本工作采用高时间分辨率和高频ESR技术对氘代蓝细菌聚球藻（Synechococcus lividus）的光系统I（PSI）进行了研究。自旋动力学测量通过监测电子自旋回波信号与不同的延迟时间后的激光闪光（ESTA）。在弱相互作用的自旋相关自由基对的假设下，动力学曲线几乎可以用两个时间常数来拟合，表明PSI中的自旋动力学涉及两种自由基对。结果表明，PSI中发生了双向电子转移。

In this work, high time resolution and high frequency ESR experiments were performed for Photosystem I (PSI) from the deuterated cyanobacterium Synechococcus lividus. Spin dynamics were measured by monitoring the electron spin echo signals with different delay times after the laser flash (DAF). Assuming a weakly interacting spin-correlated radical pair, the kinetic curve can be almost fit with two time constants, indicating that the spin dynamics involve two kinds of radical pairs in PSI. It was concluded that bidirectional electron transfer occurs in PSI.