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Progress in artificial control system for gene expression

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Chinese Science Bulletin 2000年第10期45卷 865-870页

作者： ZHANG Yong zhao nanming LIU Qiang Department of Biological Science and Biotechnology Tsinghua UniversityBeijing 100084China Department of Biological Science and Biotechnology State Laboratory of Biomembrane and Membrane BiotechnologyTsinghua UniversityBeijing 100084China

Along with the increasingly wide application of transgenic techniques, new stricter criteria have been raised for controlling the expression of exogenous genes. For these demands, a series of artificial control systems for gene expression have been developed and testified in recent years, which can control exogenous genes expression in exact time and certain level by administration of a specific drug or hormone. The successful construction of these systems offers a practicable method to control precise expression of exogenous gene in organisms, and raises the feasibility of wide application of gene therapy.

关键词： control system expression control exogenous gene.

Modeling of kiwifruit metallothionein kiwi503

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Chinese Science Bulletin 2000年第15期45卷 1413-1417,1444页

作者： Chunming Zhu Tun Lü Riqing Zhang nanming zhao Jinyuan Liu Tsing Hua Univ State Key Lab Biomembrane & Membrane Biotechnol Dept Biol Sci & Biotechnol Beijing 100084 Peoples R China

Kiwifruit metallothionein, kiwi503, is a typical plant metallothionein protein. It has 63 amino acid residues in two cysteine-rich regions and one spacer region of about 32 residues. In this note, the two cysteine-rich regions and the spacer region have been modeled separately by the distance geometry and the homology method. The three parts are then connected to generate a three-dimensional structural model of kiwifruit metallothionein kiwi503. The result shows that there is no structural or energy barrier preventing either cysteine rich domain from independently forming a metal-sulfur chelating cluster. The method can also be applied to predicting the structures of the same type of other proteins.

关键词： plant metallothionein homology distance geometry protein modeling.

Effect of calcium ions on the secondary structures of photosystemⅡ and its relations with photoinhibition

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Chinese Science Bulletin 1998年第20期43卷 1722-1727页

作者： SHI Hua YANG Kunyun XIONG Ling KUANG Tingyun zhao nanming Department of Biological Sciences and Biotechnology State Key Laboratory of Biological Membrane and Membrane BiotechnologyTsinghua UniversityBeijing 100084China Institute of Botany Chinese Academy of SciencesBeijing 100093China

Calcium ions play an important role in the oxygen_evolving process of photosystem Ⅱ as demonstrated in many experiments. The changes of the secondary structures of PS Ⅱ induced by the depletion of Ca 2+ were reported. The results indicated that the removal of Ca 2+ led to the transition of α helix to turns and sheet structures. While Ca 2+ was re_added to the media, only the structures changed to turns could be recovered. The protein conformational changes of PS Ⅱ during the donor side photoinhibition induced by the depletion of Ca 2+ were also studied. This showed that the protein conformational changes differed between the control and Ca 2+ _depleted samples in a short period of illumination (within 10 min). However, the changes became similar when the illumination time was increased.

关键词： photosystemⅡ photoinhibition calcium ions secondary structure.

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.

Amyloid precursor protein-mediated modulation of capacitive calcium entry

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Chinese Science Bulletin 2012年第35期57卷 4552-4559页

作者： MA Tuo NIU Ying zhao Chang SU ZuQi AO Qiang ZHANG XiuFang zhao nanming GONG YanDao State Key Laboratory of Biomembrane and Membrane Biotechnology School of Life SciencesTsinghua UniversityBeijing 100084China Institute of Neurological Disorders Yuquan HospitalTsinghua UniversityBeijing 100084China

Alzheimer's disease(AD) is a progressive neurodegenerative *** the present study,the function of amyloid precursor protein(APP) in modulating capacitive calcium entry(CCE),a refilling mechanism for depleted intracellular calcium stores,was *** in neural 2a(N2a) cells stably expressing wild-type human APP was lower than in wild-type N2a cells,while CCE in APP knockout mouse embryonic fibroblast(MEF) cells was higher than in their wild-type *** demonstrate that wild-type APP depresses ***,using N2a cells transfected with C-terminal APP fragments,we show that these fragments anchored in the cell membrane play an important role in CCE depression.

关键词：淀粉样前体蛋白细胞内钙库电容调制蛋白质神经变性疾病阿尔茨海默氏病胚胎成纤维细胞

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.

Endogenously generated amyloid β increases membrane fluidity in neural 2a cells

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Chinese Science Bulletin 2009年第3期54卷 394-398页

作者： NIU Ying SHENG BaiYang SONG Bo LIU LingLing ZHANG XiuFang zhao nanming GONG YanDao State Key Laboratory of Biomembrane and Membrane Biotechnology Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Medical School Tsinghua University Beijing 100084 China

The effect of endogenously generated amyloid β on membrane fluidity was investigated in Neural 2a cells stably expressing Swedish mutant amyloid precursor protein (APPswe). Membrane fluidity was studied by fluorescence polarizability using 1,6-Diphenyl-1,3,5-Hexatriene (DPH) as the fluorescence probe. It was found that the membrane fluidity in APPswe cells was significantly higher than that in its wild type counterparts. Alleviating the effect of amyloid β either by γ secretase activity inhibition or by amyloid antibody treatment decreased membrane fluidity, which indicated an important role of amyloid β in increasing membrane fluidity. Treatment using amyloid β channel blocker, tromethamine and NA4 suggested that channel formed by amyloid β on the cell membrane is a way through which amyloid β takes its membrane fluidizing effect.

关键词：膜流动性荧光极化老年痴呆症淀粉

The mitochondrial function was impaired in APP knockout mouse embryo fibroblast cells

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Chinese Science Bulletin 2009年第10期54卷 1725-1731页

作者： SHENG BaiYang NIU Ying ZHOU Hui ZHOU Hui YAN JiaXin zhao nanming ZHANG XiuFang GONG YanDao State Key Laboratory of Biomembrane and Membrane Biotechnology Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Wuhan Institute of-Biological Products Wuhan 430060 China Medical School Tsinghua University Beijing 100084 China

The amyloid precursor protein (APP) is recognized as the source of Aβ, which plays an important role in Alzheimer’s disease. However, the biological function of APP is obscure. Previous studies showed that mitochondria could be a target of APP. In this work, APP knockout mouse embryo fibroblast (MEF) cells were used to test if APP plays any role in maintaining the mitochondrial function. As the result, APP knockout MEF cells (APP-/- cells) showed the abnormal mitochondrial function, including slower cell proliferation, lower mitochondrial membrane potential, lower intracellular ROS, higher mitochondrial membrane fluidity and lower cytochrome c oxidase activity than their wild-type counterparts. However, no change was found in the amount of mitochondria in MEF APP-/-cells.

关键词：胚胎成纤维细胞线粒体膜电位亚洲功能障碍小鼠细胞色素C氧化酶阿尔茨海默氏病应用程序

Preparation of the selenome-thionine derivative of tab-toxin resistance protein

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Chinese Science Bulletin 2001年第15期46卷 1304-1307页

作者： HE Hongzhen SHAO Yu CHEN Yuhang LIU Bingbing CAO Zhenbo JIANG Fan LIU Yiwei TANG Hong LIU Jinyuan zhao nanming RAO Zihe Laboratory of Structural Biology&Protein Science Laboratory of MOE School of Life Science and EngineeringTsinghua UniversityBeijing 100084China

In order to obtain phase information for the X-ray diffraction of tabtoxin resistance protein (TTR) crystal using the MAD phasing method, a selenomethionine (Se-Met) derivative of TTR was overexpressed in E. coli strain M15, with pQE-30 plasmid, through IPTG induction in M9 medium containing Se-Met. The product was purified to an estimated homogeneity of greater than 95% according to SDS-PAGE, by a Ni-NTA metal affinity followed by a Mono Q anion exchange column chromatography. The successful substitution of Se-Met for methionine (Met) was confirmed by MALDI-TOF and ESI-Quadrupole Mass Spectrometry analysis. The derivative crystal was obtained using similar conditions as those for the native.

关键词： Se-Met TTR derivative expression purification mass spectrometry.