Mamedov Mahir, Nadtochenko Victor, Semenov Alexey
A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, 119991, Moscow, Russia,
Photosynth Res. 2015 Aug;125(1-2):51-63. doi: 10.1007/s11120-015-0088-y. Epub 2015 Feb 4.
This minireview is written in honor of Vladimir A. Shuvalov, a pioneer in the area of primary photochemistry of both oxygenic and anoxygenic photosyntheses (See a News Report: Allakhverdiev et al. 2014). In the present paper, we describe the current state of the formation of the primary and secondary ion-radical pairs within photosystems (PS) II and I in oxygenic organisms. Spectral-kinetic studies of primary events in PS II and PS I, upon excitation by ~20 fs laser pulses, are now available and reviewed here; for PS II, excitation was centered at 710 nm, and for PS I, it was at 720 nm. In PS I, conditions were chosen to maximally increase the relative contribution of the direct excitation of the reaction center (RC) in order to separate the kinetics of the primary steps of charge separation in the RC from that of the excitation energy transfer in the antenna. Our results suggest that the sequence of the primary electron transfer reactions is P680 → ChlD1 → PheD1 → QA (PS II) and P700 → A 0A/A 0B → A 1A/A 1B (PS I). However, alternate routes of charge separation in PS II, under different excitation conditions, are not ruled out.
本微型综述是为纪念弗拉基米尔·A·舒瓦洛夫而撰写的,他是有氧和无氧光合作用初级光化学领域的先驱(见新闻报道:阿拉赫韦尔季耶夫等人,2014年)。在本文中,我们描述了有氧生物中光系统(PS)II和I内初级和次级离子自由基对形成的当前状态。现在已有关于PS II和PS I中初级事件的光谱动力学研究,这些研究是在~20飞秒激光脉冲激发下进行的,并在此进行综述;对于PS II,激发中心波长为710nm,对于PS I,激发中心波长为720nm。在PS I中,选择条件以最大程度地增加反应中心(RC)直接激发的相对贡献,以便将RC中电荷分离的初级步骤的动力学与天线中激发能量转移的动力学区分开来。我们的结果表明,初级电子转移反应的顺序是P680→ChlD1→PheD1→QA(PS II)和P700→A 0A/A 0B→A 1A/A 1B(PS I)。然而,在不同激发条件下,PS II中电荷分离的替代途径并未被排除。