Studies on the Photochemical Reaction Center Complexes of Photosynthesis

光合作用光化学反应中心配合物的研究

基本信息

批准号：
63044148
负责人：
MURATA Norio
金额：
$ 13.44万
依托单位：
National Institute for Basic Biology
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

One of the most important processes of photosynthesis is the photochemical reaction that converts light energy into chemical energy. Various kinds of protein complexes, which perform the photochemical reactions, are available, and are used in this study. The results are summarized as follows : (1) Photosystem II complex - (a) Plastoquinone of the cyanobacterial photosystem II complex was substituted by many kinds of quinone derivatives, and we found that tetrahalobenzene most efficienty bound to the photosystem II complex and was a most efficient electron acceptor. (b) The oxygen-evolving activity of the photosystem II complex was greatly stabilized by glycinebetaine.(2) Photosystem I complex - (a) Selective destruction of FeS centers of the photosystem I complex demonstrated that both FeS centers A and B are essential to the electron transport. (b) In the reconstitution experiment with liposomes, it was suggested that monogalactolipid accelerates the transfer of excitation energy from the light-harvesting chlorophyll protein to the photosystem I complex.(3) Bacterial reaction center complex - (a) The reaction center complex from Heliobacterium contained two molecules of bacteriochlorophyll g' and two molecules of a chlorophyll a-like pigment. (b) We studied the absorption and the CD spectra of monomer, dimer, trimer and polymer of Bacteriochlorophyll c which were formed in water - saturated CCl_4.(4) Photosynthesis genes - (a) We purified from germinating wheat an enzyme which methanolizes plastid DNA. (b) We cloned genes of the chloroplast genome which encode small polypeptides of the photosystem II complex. (c) The tissuespecific expression of phosphoenolpyruvate carboxylase (PEPcase) was studied by ligating the promoter region of PEPcase gene with a reporter gene. The transcription of the gene for the C_4 type, but not C_3 type, of PEPcase was enhanced by NH_3.

光合作用最重要的过程之一是光化学反应将光能转化为化学能。可以使用各种执行光化学反应的蛋白质复合物，并在本研究中使用。结果总结如下：（1）光系统II复合物 - （a）蓝细菌光系统II复合物的质喹酮由多种类型的喹酮衍生物代替，我们发现四氢苯二苯二苯二烯酮最有效地绑定到Photosystem II II，并且是最有效的电子受体。（b）光系统II复合物的氧气不断发展的活性被甘氨酸甲虫大大稳定。（2）光系统I复合物 - （a）选择性破坏光系统I复合物的FES FES中心，证明了两个FES中心A和B对电子传输都是必不可少的。（b）在对脂质体的重建实验中，建议单次乳糖化加速了激发能量从轻度收获的叶绿素蛋白到光系统I复合物的传递。色素。（b）我们研究了单体，二聚体，三聚体和聚合物的吸收和CD光谱，这些菌氯叶藻的C的聚合物是在水-A饱和的CCL_4中形成的。（4）光合作用基因 - （a）我们从发芽的小麦中纯化的麦芽糖纯化的酶，这些酶是硫化质体DNA的。（b）我们克隆了叶绿体基因组的基因，该基因编码光系统II复合物的小多肽。（c）通过用报告基因的pepcase Gene的启动子区域绑扎磷酸烯醇丙酮酸羧化酶（PEPCASE）的组织特异性表达。 NH_3增强了Pepcase的C_4类型基因的转录，但不是C_3类型。