Characterization of the water oxidizing complex of photosystem II of the Chl d-containing cyanobacterium Acaryochloris marina via its reactivity towards endogenous electron donors and acceptors.
Characterization of the water oxidizing complex of photosystem II of the Chl d-containing cyanobacterium Acaryochloris marina via its reactivity towards endogenous electron donors and acceptors.
复制标题
通过其对内源电子供体和受体的反应性来表征含叶绿藻 Acaryocholis marina 的光系统 II 的水氧化复合物。
DOI：
10.1039/b604389e
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
G. Renger
中科院分区：
文献类型：
--
作者：
D. Shevela;Birgit Nöring;H. Eckert;J. Messinger;G. Renger
Acaroychloris（A.）玛丽娜是一种独特的产氧生物，含有大量的叶绿素d（Chl d）和很少的Chl a分子。这一特征引起了人们对光敏色素性质的质疑，光敏色素支持光系统II（PS II）中光诱导的氧化水分解。在这项研究中，闪光诱导的析氧模式（FIOPs）的测量，以解决的问题是否S（i）状态的跃迁概率和/或水氧化复合物（WOC）在其不同的S（i）状态的氧化还原电位改变在A。与菠菜类囊体相比，在不同版本的Kok模型的框架内对所获得的数据进行分析表明，在光激活的A。与菠菜类囊体相比，marina细胞的错过概率相似。这一发现表明，WOC内反应中心（P680）和Y（Z）的氧化还原电位和动力学对于两种生物体几乎是相同的。这一结论得到了S（2）和S（3）态寿命测量的有力支持。对于失活的缓慢阶段，获得了几乎相同的时间常数。在S（2）和S（3）衰变快相，A. marina细胞和菠菜类囊体反映了Y（D）/Y（D）（ox）的E（m）在前者中比在后者中更低的值的偏移，如通过观察到S（0）被Y（D）（ox）氧化为S（1）的动力学中的相反变化所揭示的。A的双中概率略有增加。与菠菜类囊体相比，玛丽娜细胞中的Q（A）（-）到Q（B）电子转移更快。
Acaroychloris (A.) marina is a unique oxygen evolving organism that contains a large amount of chlorophyll d (Chl d) and only very few Chl a molecules. This feature raises questions on the nature of the photoactive pigment, which supports light-induced oxidative water splitting in Photosystem II (PS II). In this study, flash-induced oxygen evolution patterns (FIOPs) were measured to address the question whether the S(i) state transition probabilities and/or the redox-potentials of the water oxidizing complex (WOC) in its different S(i) states are altered in A. marina cells compared to that of spinach thylakoids. The analysis of the obtained data within the framework of different versions of the Kok model reveals that in light activated A. marina cells the miss probability is similar compared to spinach thylakoids. This finding indicates that the redox-potentials and kinetics within the WOC, of the reaction center (P680) and of Y(Z) are virtually the same for both organisms. This conclusion is strongly supported by lifetime measurements of the S(2) and S(3) states. Virtually identical time constants were obtained for the slow phase of deactivation. Kinetic differences in the fast phase of S(2) and S(3) decay between A. marina cells and spinach thylakoids reflect a shift of the E(m) of Y(D)/Y(D)(ox) to lower values in the former compared to the latter organisms, as revealed by the observation of an opposite change in the kinetics of S(0) oxidation to S(1) by Y(D)(ox). A slightly increased double hit probability in A. marina cells is indicative of a faster Q(A)(-) to Q(B) electron transfer in these cells compared to spinach thylakoids.