论文标题
通过多光谱二维电子光谱解决的光系统II反应中心的电荷分离
Charge Separation in the Photosystem II Reaction Center Resolved by Multispectral Two-Dimensional Electronic Spectroscopy
论文作者
论文摘要
光系统II反应中心（PSII-RC）执行了氧光合作用的主要能量转换步骤。尽管对PSII-RC进行了广泛的研究，但能量转移和电荷分离的相似时间尺度，并且QY区域中严重重叠的颜料过渡导致了多种电荷分离机理和激子结构的多种模型。在这里，我们将二维电子光谱（2DE）与连续探针和二维电子振动光谱（2DEV）相结合，以77K研究Cyt B559-D1D2 PSII-RC。这种多光谱组合将重叠的QY激子与独特的阴离子和色素特异性QX和MID-IR转变相关联，以解决电荷分离机理和激子结构。通过对多光谱2D数据的广泛分析，我们发现电荷分离通过单个途径在高度离界化激发态上进行多个时间尺度进行，其中Pheod1是主要电子受体，而CHLD1和PD1和PD1合作用作主要电子供体。
The photosystem II reaction center (PSII-RC) performs the primary energy conversion steps of oxygenic photosynthesis. While the PSII-RC has been studied extensively, the similar timescales of energy transfer and charge separation, and the severely overlapping pigment transitions in the Qy region have led to multiple models of its charge separation mechanism and excitonic structure. Here we combine two-dimensional electronic spectroscopy (2DES) with a continuum probe and two-dimensional electronic vibrational spectroscopy (2DEV) to study the cyt b559-D1D2 PSII-RC at 77K. This multispectral combination correlates the overlapping Qy excitons with distinct anion and pigment-specific Qx and mid-IR transitions to resolve the charge separation mechanism and excitonic structure. Through extensive simultaneous analysis of the multispectral 2D data we find that charge separation proceeds on multiple timescales from a highly delocalized excited state via a single pathway in which PheoD1 is the primary electron acceptor, while ChlD1 and PD1 act in concert as the primary electron donor.
