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Study on the photosynthetic mechanism by spectroscopic measurements of cyanobacterial mutants

蓝藻突变体的光谱测量研究光合机制

基本信息

批准号：
14540607
负责人：
NOGUCHI Takumi
金额：
$ 2.37万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540607/
关键词：
Photosynthesis Photosystem II cyanobacteria Fourier transform infrared spectroscopy 熱発光らん藻

项目摘要

We have examined the structure and reactions of photosystem II (PSII) complexes by analyzing the mutants of the thermophilic cyanobacterium Thermosynechococcus elongatus by means of light-induced Fourier transform infrared (FTIR) difference spectroscopy. The following results were obtained.1.Using the highly active PSII core complexes in which the CP43 protein is histidine tagged, the reaction mechanism of the water oxidation was studied. We have for the first time detected the reactions of substrate water in the individual S-state transitions (S_1→S_2,S_2→S_3,S_3→S_0,S_0→S_1) in the reaction cycle as the changes in FTIR bands of the water OH stretches (3500-3650 cm^<-1>). The changes in the amino acid side chains and polypeptide backbones were also identified using ^<13>C and ^<15>N isotope substitution. Furthermore, pH dependence of the individual S-state transitions was studied by measurements of flash-induced FTIR spectra of S-state cycle at various pHs. Remarkable inhibition in the acidic region was observed in the three S-state transitions other than the S_1→S_2, indicating the presence of proton release at these transitions.2.We have prepared the T.elongatus mutant in which D2-Tyr160 (YD) was replaced with Phe (D2-Y160F) and studied the role of Y_D, the peripheral electron donor to the primary electron donor chlorophyll P680. The FTIR difference spectrum upon light-induced P680 formation of the D2-Y160F mutant showed a clear downshift of carbomethoxy C=O stretching band at 1751 cm^<-1> observed in WT. This observation indicates that Y_D interacts with P680 by a hydrogen-bonding network and it is suggested that the oxidation status of Y_D controls the redox potential of P680 through this interaction.

我们已经研究了光系统II（PSII）复合物的结构和反应，通过光诱导傅里叶变换红外（FTIR）差光谱分析的嗜热蓝细菌细长热聚球藻的突变体。主要研究结果如下：1.利用组氨酸标记的高活性PS Ⅱ核心复合物，研究了水氧化反应的反应机理。我们首次探测到反应循环中底物水在各个S态跃迁（S_1→ S_2，S_2 → S_3，S_3 → S_0，S_0 →S_1）中的反应与水OH伸缩峰（3500-3650 cm ~ 2）的FTIR谱带变化<-1>一致。还使用^ C和^ N同位素取代鉴定了氨基酸侧链和多肽主链的变化<13><15>。此外，通过测量不同pH下的S-态循环的闪光诱导FTIR光谱，研究了单个S-态转变的pH依赖性。2.制备了以Phe（D2-Y160 F）取代D2-Tyr 160（YD）的长体藻突变体，并研究了主要电子供体叶绿素P680的外围电子供体Y_D的作用。D2-Y160 F突变体的光诱导P680形成后的FTIR差谱显示在WT中观察到的1751 cm-2处的甲氧羰基C=O伸缩带的明显下移<-1>。这表明Y_D与P680通过氢键网络相互作用，并推测Y_D的氧化态通过这种相互作用控制P680的氧化还原电位。

项目成果

期刊论文数量（62）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Monolayers of natural and recombinant photosystem II on gold electrodes-Potentials for use as biosensors for detection of herbicides

金电极上天然和重组光系统 II 的单层-用作检测除草剂的生物传感器的潜力

DOI：
发表时间：
2004
期刊：
Analytical Letters 37
影响因子：
0
作者：
H.Suzuki;Y.Fukushima;A.Boussac;K.Kondo;A.Kita;H.Suzuki;Y.Fukushima;A.Kita;T.Noguchi;H.Suzuki;A.Boussac;J.Maly;H.Suzuki;M.Sugiura;D.Kirilovsky;J.Maly;M.Iwai;M.Kobayashi;N.Sato;R.Narikawa;M.Iwai;S.Yoshihara;S.Yoshihara;M.Sugiura;J.Maly
通讯作者：
J.Maly

T.Noguchi: "Analysis of flash-induced FTIR difference spectra of the S-state cycle in the photosynthetic water-oxidizing complex by uniform ^<15>N and ^<13>C isotope labeling"Biochemistry. 42・20. 6035-6042 (2003)

T.Noguchi：“通过均匀 ^<15>N 和 ^<13>C 同位素标记分析光合水氧化复合物中 S 态循环的闪光诱导 FTIR 差异光谱”生物化学 42・20。 6042 (2003)