Production of reactive oxygen species in chloride- and calcium-depleted photosystem II and their involvement in photoinhibition
Production of reactive oxygen species in chloride- and calcium-depleted photosystem II and their involvement in photoinhibition
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DOI：
10.1016/j.bbabio.2003.12.003
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发表时间：
2004-02-15
影响因子：
4.3
通讯作者：
Krieger-Liszkay, A
中科院分区：
文献类型：
--
作者：
Arató, A;Bondarava, N;Krieger-Liszkay, A
研究了光系统II(PSII)样品的光敏感度。在氯离子耗竭的PSII存在下，活性中心受到更严重的破坏，很可能是由于在非功能中心形成了更多的活性氧物种所致。氯离子耗竭导致过氧化氢产生增加，这可能是导致PSII活性丧失的原因之一。为了区分部分水氧化直接生成H_2O_2和氧还原间接生成H_2O_2涉及到O-2(-)的生成，用自旋捕捉EPR光谱跟踪了活性氧物种的产生。所有被研究的样品，即具有功能的水分裂复合体的PSII，在光照O-2(-.)时产生的耗尽钙和氯的PSII。还有哦。受体侧的自由基，而耗氯的PSII产生额外的OH。来源于过氧化氢的自由基在PSII的供体侧形成。(C)2004爱思唯尔B.V.保留所有权利。
Mixed photosystem II (PSII) samples consisting of Cl--depleted and active, or Ca2+-depleted and active PSII enriched membrane fragments, respectively, were investigated with respect to their susceptibility to light. In the presence of Cl--depleted PSII, active centers were damaged more severely, most likely caused by a higher amount of reactive oxygen species formed in the nonfunctional centers. Cl- depletion led to an increased H2O2 production, which seemed to be responsible for the stimulation of PSII activity loss. To distinguish between direct H2O2 formation by partial water oxidation and indirect H2O2 formation by oxygen reduction involving the prior formation of O-2(-.), the production of reactive oxygen species was followed by spin trapping EPR spectroscopy. All samples investigated, i.e. PSII with a functional water splitting complex, Ca2+- and Cl--depleted PSII, produced upon illumination O-2(-.) and OH. radicals on the acceptor side, while Cl-depleted PSII produced additionally OH. radicals originating from H2O2 formed on the donor side of PSII. (C) 2004 Elsevier B.V. All rights reserved.