Superoxide, hydrogen peroxide and hydroxyl radical in D1/D2/cytochrome b-559 Photosystem II reaction center complex
Superoxide, hydrogen peroxide and hydroxyl radical in D1/D2/cytochrome b-559 Photosystem II reaction center complex
复制标题
D1/D2/细胞色素 b-559 光系统 II 反应中心复合体中的超氧化物、过氧化氢和羟基自由基
DOI：
10.1023/b:pres.0000028340.44043.6c
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发表时间：
2004-07-01
影响因子：
3.7
通讯作者：
Liu, Y
中科院分区：
文献类型：
--
作者：
Liu, K;Sun, J;Liu, Y
用自旋捕集电子自旋共振（ESR）技术研究了D1/D2/细胞色素B-559光系统Ⅱ反应中心（PS Ⅱ RC）复合物中超氧阴离子自由基和羟自由基的形成。当PS II RC复合物被强烈照射时，在泛醌的存在下检测到超氧化物。在PS Ⅱ RC复合物中检测到SOD活性。超氧化物的主要产物过氧化氢，导致产生最具破坏性的活性氧物质（OH）-O-，在PS II钢筋混凝土照明复杂。进一步研究了泛醌、SOD和H_2O_2对PS Ⅱ RC复合物中色素光漂白和蛋白质光损伤的作用。泛醌保护PS II RC复合物免受光损伤，有趣的是，外源性SOD促进这种损害。所有这些结果表明，PS II RC是一个活性位点的超氧化物及其衍生物的产生，这一过程保护生物体在强光下，可能通过抑制更有害的ROS，如单线态氧。
Spin-trapping electron spin resonance (ESR) was used to monitor the formation of superoxide and hydroxyl radicals in D1/D2/cytochrome b-559 Photosystem II reaction center (PS II RC) Complex. When the PS II RC complex was strongly illuminated, superoxide was detected in the presence of ubiquinone. SOD activity was detected in the PS II RC complex. A primary product of superoxide, hydrogen peroxide, resulted in the production of the most destructive reactive oxygen species, (OH)-O-., in illuminated PS II RC complex. The contributions of ubiquinone, SOD and H2O2 to the photobleaching of pigments and protein photodamage in the PS II RC complex were further studied. Ubiquinone protected the PS II RC complex from photodamage and, interestingly, extrinsic SOD promoted this damage. All these results suggest that PS II RC is an active site for the generation of superoxide and its derivatives, and this process protects organisms during strong illumination, probably by inhibiting more harmful ROS, such as singlet oxygen.