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Mutagenesis of Ser^(24) of cytochrome b559 α subunit affects PSII activities in Chlamydomonas reinhardtii

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Chinese Science Bulletin 2007年第7期52卷 896-902页

作者： MA JingJing li liangbi JING YuXiang KUANG TingYun Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of Sciences Beijing 100093 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

In order to study the functions of cytochrome b559 (Cyt b559) in photosystem two (PSII) activity, mutant S24F of Chlamydomonas reinhardtii was constructed using site directed mutagenesis, in which Serine24 (Ser24) locating downstream of Histidine23 (His23) in α subunit of Cyt b559 was replaced by Phenylalanine (Phe). Physiological and biochemical analysis showed that mutant S24F could be grown photoautotrophically or photoheterotrophically. However, their growth rate was slower either on HSM or TAP medium than that of the control; Analysis of PSII activity revealed that its oxygen evolution was about 71% of wild type (WT); The Photochemical efficiency of PSII (Fv/Fm) of S24F was reduced 0.23 compared with WT; S24F was more sensitive to strong light irradiance than the wild type; Furthermore, SDS-PAGE and Western-blotting analysis indicated that the expression levels of α subunit of Cyt b559, LHCII and PsbO of S24F were a little less than those of the wild type. Overall, these data suggests that Ser24 plays a significant role in making Cyt b559 structure maintain PSII complex activity of oxygen evolution although it is not directly bound to heme group.

关键词：莱茵衣藻细胞色素b559α亚基丝氨酸残基 Ser24 突变光系统II 光合活性

New structure model of oxygen-evolving center and mechanism for oxygen evolution in photosynthesis

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Chinese Science Bulletin 1999年第24期44卷 2209-2215页

作者： Chunxi Zhang Jie Pan liangbi li Tingyun Kuang Chinese Acad Sci Inst Bot Photosynth Res Ctr Beijing 100093 Peoples R China

So far, many important questions and problems concerning the structure and mechanism of photosynthetic oxygen evolution are still unsolved. On the basis of recent achievements in this field, a new structure model is proposed whereby two H2O molecules bind asymmetrically to two manganese ions (Mn1Ⅱ and Mn4Ⅲ) at the open end of 'C' shaped cluster and keep rather large distance. Two histidine residues coordinate to the other two manganese ions in higher oxi-

关键词： photosynthesis photosystem Ⅱ . oxygen-evolving center mechanism of oxygen evolution.

33 ku protein associated several polypeptides with nearly the same molecular weight but not the same isoelectric point

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Chinese Science Bulletin 2000年第1期45卷 57-60页

作者： Hui Yu Bin Kang Jie Wei liangbi li Tingyun Kuang Chinese Acad Sci Inst Bot Photosynth Res Ctr Beijing 100093 Peoples R China

The 33 ku protein, prepared from NaCI-treated PSII particles, has shown an single band by SDS-PAGE. After being dialyzed against the low-osmotic medium at 4癈, it has been found that the 33 ku protein degraded into several small fragments. This result suggests that the preparations of 33 ku protein probably contain some latent proteinases. it has also been found, by the 2-D electrophoresis and IEF, that the preparations of 33 ku protein not dialyzed against the low-osmotic medium contain several polypeptides with nearly the same molecular weight but not the same isoelectric point as the 33 ku protein.

关键词： 33 ku protein proteinase isoelectric point isoelectric focusing 2-D (2-dimensional) electrophoresis.

Simulation for the primary electronic donor of photosystem II in vitro

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Chinese Science Bulletin 2000年第10期45卷 914-920页

作者： PAN Jie ZHANG Chunxi GONG Yandao li liangbi ZHAO Nanming KUANG Tingyun Photosynthesis Research Center Institute of BotanyChinese Academy of SciencesBeijing 100093China National Laboratory of Biomembranes and Membrane Biotechnology Department of Biological Science and BiotechnologyTsinghua UniversityBeijing 100084China Laboratory of Optical Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080China

Histidine coordinated to Chl a is a distinct characteristic of Chl a in vivo. By usinghistidine analogue of 1-methylimidazole (C4H6N2) and measuring the UV/vis absorption, CD and MCD spectra of the interaction between C4H6N2and Chl a in CCI4, we have obtained that: (i) In pure CCI4 solvent, Chl a molecule is in five-coordinate state, and two Chl a molecules form an asymmetric compact-dimer with strong coupling interaction. We propose that the two Chl a molecules are connected by two unequally coordinated Mg-O bonds (the two oxygen atoms come from the C=O of C131 keto and C17 ester, respectively); (ii) when the molar ratio of C4H6N2/Chl a is 0.5 or 1 (corresponding to 2Chl a #1C4H6N2 and 2Chl a ·2C4H6N2, respectively), significant changes have been observed in the absorption, CD and MCD spectra, which indicate that the Chl a remains in dimer form, but the coupling interaction between them reduces greatly. We postulate that C4H6N2 replaces the ligation of C=O of C17 ester and C131 keto to Mg atoms

关键词： photosynthesis Chl a histidine coordination P680 simulation spectroscopy research.

Positional distribution of fatty acids on the glycerol backbone during the biosyn-thesis of glycerolipids in Ectocarpus fasciculatus

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Chinese Science Bulletin 2002年第21期47卷 1802-1806页

作者： XU Yinong WANG Zeneng VAN Xiaojun liN Wei li liangbi KUANG Tingyun Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of BotanyChinese Academy of SciencesBeijing 100093China Key Laboratory of Experimental Marine Biology Institute of Marine BiologyChinese Academy of SciencesQingdao 266071China

The biosynthesis of glycolipids in ***-tus was studied by 14C label and chase. The fatty acids in sulphoquinovosyl diacylglycerol (SQDG) were almost 16-car-bon and 18-carbon ones. In addition to the two fatty acids, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) contained 8.5 mol% and 31.0 mol% of eicosapentaenoic acid (20 : 5), respectively, and this fatty acid was usually distributed in the sn-1 position of the glyc-erol backbone. When plants were incubated with [2-14C] acetate, differences existed in the positional distribution of the labeled fatty acids in sn-1 and sn-2 among the three glycerolipids. In SQDG, 14C-labeled fatty acids were distributed uniformly in the sn-1 and sn-2 positions. In DGDG, 14C-labeled fatty acids were mainly distributed in the sn-2 position. In MGDG, the radioactivity of fatty acids in sn-1 position was far greater than that in sn-2 position after a 30 min pulse label, and the difference in radioactivity between the two positions

关键词： E. fasciculatus glycerolipid fatty acid isotope label.

The photodamage process of pigments and proteins of PSI complexes from Spinacia Oleracea L.

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Chinese Science Bulletin 2001年第21期46卷 1812-1816页

作者： WEI Jie YU Hui li liangbi KUANG Tingyun WANG Jushuo GONG Yandao ZHAO Nanming Laboratory of Photosynthesis Basic Research Institute of BotanyChinese Academy of SciencesBeijing 100093China Department of Biological Science and Biotechnology Tsinghua UniversityBeijing 100084 China

Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complexes was investigated using absorption, fluorescence, circular dichroism (CD) spectroscopy and SDS-PAGE. It was found from the optical absorption spectra that the maximal ab-sorbance of PSI complexes decreased and maximal peaks blue-shifted during the illumination, and the forth derivative spectra demonstrated that the absorbance decreasing at red region mainly resulted from the aborbance decreasing of the long wavelength Chla, implying that the long-wavelength Chla was readily to be bleached. The CD signals contributed by LHCI decreased more rapidly than other CD signals con-tributed by Chla and Carotenoid, indicating that the LHCI was more sensitive to light than core complexes. It was observed by SDS-PAGE that some small polypeptides of PSI complexes were damaged earlier than reaction

关键词： PSI pigment-protein complex photodamage LHCI absorption spectra CD spectra.

Thermal stability of oxygen evolution in photosystem Ⅱ core complex in the presence of digalactosyl diacylglycerol

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Chinese Science Bulletin 2002年第24期47卷 2089-2092页

作者： YANG Zhenle, li liangbi & KUANG TingyunPhotosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China Photosynthesis Research Center Institute of Botany Chinese Academy of Sciences Beijing China

The influence of digalactosyldiacylglycerol (DGDG), one of the photosynthetic membrane lipids, on heat inactivation of the process of oxygen evolution has been studied in vitro in photosystem Ⅱ(PS Ⅱ) core complex. It was found that the temperature of semi-inactivation of oxygen evolution in the complex increased from 40.0 to about 43.0℃ in the presence of DGDG with 5-min heat treatment in the dark. Furthermore, when PS Ⅱ core complex was incubated for 5 min at 45.0℃, the oxygen evolution in the complex was completely lost, whilst the DGDG-complexed PS Ⅱ core complex still retained a 16% of activity (100% for 25.0℃). In addition, a 1-h incubation at 38.0℃ inactivated absolutely the oxygen evolution for the PS Ⅱ core complex. By contrast, there remained about 20% of activity (zero time for 100%) for the complex in the presence of DGDG under the same condition. These results indicate a new role of DGDG in the protection of PS Ⅱ core complex against the deleterious effects of temperature. It was

关键词： digalactosyl diacylglycerol photosystem Ⅱ core complex extrinsic protein of 33 kD thermal stability oxygen evolution.

Effects of different aggregation forms of LHC Ⅱ from Bryopsis corticulans on the excited state properties of Chl a

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Chinese Science Bulletin 2006年第12期51卷 1444-1451页

作者： ZUO Ping CHEN Hui WU Yishi SHEN Shihua WANG Peng AI Xicheng ZHANG Jianping li liangbi KUANG Tingyun State Key Laboratory for Structural Chemistry of Stable and Unstable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of Sciences Beijing 100093 China

Steady-state and time-resolved fluo- rescence spectroscopies have been used to study the excited state properties of Chl a in different ag- gregation forms of light-harvesting complex II (LHC II) from an intertidal green alga, Bryopsis corticulans, i.e. LHC II monomer, trimer and oligomer. When either Chl a or Chl b was selectively excited, the observed decrease in Chl a fluorescence in the oligomer is proved to be caused mainly by the fast fluorescence quenching among Chl a molecules, rather than by the decrease in Chl b-to-Chl a singlet excitation transfer efficiency. Analyses of the picosecond time-resolved fluorescence kinetics identified two exponential de- cay components in all of the three forms of LHC II: a longer-lived component (4.1―4.7 ns) originating from fluorescence emission of Chl a, and a shorter-lived one (135―540 ps) from the rapid equilibration of singlet excitation among Chl a molecules. The time constant of excitation equilibration is 135 ps in oli- gomer, 520 ps in trimer and 540 ps in monomer. These results imply that LHC II in oligomer form is inherently able to quench Chl a excitation, a mecha- nism which may be related to the photoprotection of PS II via changing the degree of LHC II aggregation in Bryopsis corticulans.

关键词： LHC Ⅱ 聚集形式 Chl a 荧光光捕获化合物能量转变

Phosphatidylglycerol effect on oxygen-evolving activity in Ca^(2+)-depleted photosystem Ⅱ

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Chinese Science Bulletin 2000年第21期45卷 1964-1968页

作者： YANG Zhenle, li liangbi, XU Yinong & KUANG TingyunLaboratory of Photosynthesis Basic Research, Institute of Botany, Chinese Academy of Sciences, Beijing 100093. China Laboratory of Photosynthesis Basic Research Institute of Botany Chinese Academy of Sciences Beijing China

The ettect of anionic phosphatidylglycerol (HG) on oxygen evolution in a photosystem Ⅱ (PS Ⅱ) particle depleted of Ca2+ (designated dCaPS Ⅱ) has been investigated. The major finding is the observation of a new role of PG in the PS Ⅱ function. That is, PG restores nearly the lost oxygen evolution in dCaPS Ⅱ particle owing to Ca2+ depletion to the levels in intact PS Ⅱ . Furthermore, there is a stimulation of oxygen-evolving activity in the dCaPSⅡ complexed with PG in the presence of exogenous CaCI2, which PG enhances increasingly oxygen evolution with increasing CaCI2 concentration. It is suggested that PG-induced oxygen evolution recovery of dCa PS Ⅱresumption of normal structure in protein by PG effect, whereas the enhancement of oxygen evolution in complex subject to CaCI2 is ascribed to the optimization of such a structure due to coordination complex formation of Ca2+ ions with PG.

关键词： photosystem Ⅱ Ca2+-depleted photosystem Ⅱ phosphatidylglycerol Ca2+ oxygen-evolving activity.