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AlkB recognition of a bulky DNA base adduct stabilized by chemical cross-linking

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Science China chemistry 2010年第1期53卷 86-90页

作者： YI ChengQi1 & HE Chuan1,2.1Department of chemistry,university of Chicago,Chicago,Illinois 60637,USA 2.epartment of Chemical Biology,{2. of chemistry and molecular engineering,peking university,beijing 100871,China 1. Department of chemistry University of Chicago Chicago Illinois 60637 USA2. Department of Chemical Biology College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

*** AlkB is a direct DNA/RNA repair protein that oxidatively reverses N1 alkylated purines and N3 alkylated pyrimidines to regular *** crystal structures have revealed N1-methyl adenine(1-meA) recognition by AlkB and a unique base flipping mechanism,but how the AlkB active site can accommodate bulky base adducts is largely *** a previously developed chemical cross-linking technique,we crystallized AlkB with a duplex DNA containing a caged thymine base(cagedT).The structure revealed a flexible hairpin lid and a reorganized substrate recognition loop used by AlkB to accommodate *** observations demonstrate,at the molecular level,how bulky DNA adducts may be recognized and processed by AlkB.

关键词： DNA/RNA repair AlkB caged thymine disulfide cross-linking bulky base adduct

Status of study on biological and toxicological effects of nanoscale materials

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Science China chemistry 2005年第5期48卷 385-394页

作者： WANG Bing1, FENG Weiyue1, ZHAO Yuliang1, XING Gengmei1, CHAI Zhifang1, WANG Haifang2.& JIA Guang3 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, beijing 100049, China 2. college of chemistry and molecular engineering,{2., beijing 100871, China 3. Department of Occupational and Environmental Health Sciences, School of Public Health,{2., beijing 100083, China 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China 2. college of chemistry and molecular engineering Peking University 100871 Beijing China 3. Department of Occupational and Environmental Health Sciences School of Public Health Peking University 100083 Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

Adjoint method for the optimum planning of industrial pollutant sources

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Science China Earth Sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2. HU Fei2.& ZHU Jiang2.1. college of Environmental Sciences, peking university,{2., China 2. LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., China 1. college of Environmental Sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

Mapping the Antigenic Peptides of Sm2./2.in Glutathione S-Transferases of Schistosoma Mansoni

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Chinese Chemical Letters 1998年第4期9卷 377-379页

作者： Jia Xi XU Meng Shen CAI(college of chemistry and{2. engineering, peking university, beijing 100871 (School of Pharmaceutical Sciences, beijing Medical university, beijing 100083) peking Univ Coll Chem & Mol Engn Beijing 100871 Peoples R China beijing Med Univ Sch Pharmaceut Sci Beijing 100083 Peoples R China

Six antigenic peptides of Sm2./2.glutathione S-transferase of schistosoma mansoni have been predicted according to their hydrophilicity, flexibility, accessibility, charge distribution and beta-turn in the secondary structure by the determination of its primary structure, and synthesized by solid phase method. Two of them showed good antigenicity by Dot-ELISA. They would be candidate peptides of synthetic anti-schistosomal vaccine.

关键词： schistosoma mansoni glutathione S-transferase antigenic peptide peptide vaccine

A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL POLYMERIZATION OF STYRENE

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Chinese Journal of Polymer Science 2001年第5期19卷 441-445页

作者： Shu-hui Qin Dong-qi Qin Kun-yuan Qiu Department of Polymer Science and engineering college of{2. and molecular engineering peking university beijing 100871, China beijing Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

A novel photo-induced initiating system, 2.2.dimethoxy-2.phenylacetophenone (DMPA)/ferric tri(NN-diethyldithiocarbamate) [Fe(DC)(3)], was developed and used for the atom transfer radical polymerization (ATRP) of styrene in toluene. The polymerization proceeds with DMPA as photo-initiator, Fe(DC)(3) as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the polymerization mechanism revealed by end group analysis belongs to a reverse ATRP. Block copolymer was prepared by using thus obtained PSt as macroinitiator and Fe(DC)(2. as catalyst under UV light irradiation via a conventional ATRP process.

关键词： photo atom transfer radical polymerization living radical polymerization well-defined polystyrene block copolymer

Small Peptide Interacting with Pollen Calmodulinand their Effects on Cellular Functions

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Chinese Chemical Letters 1999年第11期10卷 929-932页

作者： Jing SU Yan Ling SONG Min HU(college of chemistry and{2. engineering, peking university, beijing 100871)(State Key Laboratory of Environmental Simulation and Pollution Control,peking university. beijing 100871) peking Univ Coll Chem & Mol Engn Beijing 100871 Peoples R China peking Univ State Key Lab Environm Simulat & Pollut Control Beijing 100871 Peoples R China

The interaction between dansyl-labeled pollen calmodulin (D-pCaM) and synthesized peptides was studied in the presence of Ca2. by fluorescence spectra. It is Found that Gly/L-Ala --> D-Ala substitution in peptide chains caused great changes in their affinity for pCaM. Besides. our data provided evidence on the dissimilarity of different CaMs although they have highly-conserved structures. A preliminary study was carried out on the effects of CaM-binding peptides on cellular signal transduction, cell proliferation, showing the participation of CaM in cell functions mentioned above.

关键词： pollen calmodulin affinity cellular signal transduction cell proliferation

Biotic communities of the marine ecosystem in Meizhou Bay

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Journal of Environmental Sciences 1996年第1期8卷 48-56页

作者： Ren Jiuchang Cai Xiaoming (Center of Environmental Sciences,peking university,{2.,China)Chen Bin(college of Life Sciences, peking university,{2., China )Li Peng(college of chemistry and molecular engineering, peking university, Bei Ctr of Envmtl Sci Peking Univ Beijing China China

The current situation of biotic communities in Meizhou Bay is presented in this *** species composition,seasonal variation,and distribution of phytoplankton,zooplankton, red tide organisms,fishes,and benthos in Meizhou Bay were investigated,and the content of chlorophyll a and primary production and their seasonal variation were also *** water quality of Meizhou Bay was monitored by measuring the density of Escherichia coli. Results reveal that there is a great variety of species in Meizhou Bay and the water in Meizhou Bay is *** the individual numbers of various organisms are very low, especially those of ***,there are more than 40 species of red tide organisms and there exist opportunities of red tides between May and *** these demand cautious be taken in the future development of this area although it has great environment capacity.

关键词： biotic community marine ecosystem Meizhou Bay.

SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER

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Chinese Journal of Polymer Science 2002年第5期20卷 401-407页

作者： Lifang Yang Haifeng He Hongqing Cao Xinhua Wan Qi-feng Zhou Department of Polymer Science & engineering college of{2. & molecular engineering peking university beijing 100871, China peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China

Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl to quinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M-w ca. 750) as flexible segments, were synthesized. The chemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by H-1-NMR and MALDI-TOF mass spectrometry. The diblock oligomers showed good solubility in common organic solvents and aggregated in water as characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescence and formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant that this effort might lead to commercial important highly organized functional materials.

关键词： rod-coil diblock oligomer MALDI-TOF mass spectrometry microfibrilla aggregate fractal-like pattern

A New Competitive Inhibitory Monoclonal Antibody to Carboxypcptidase A(CPA)

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Chinese Chemical Letters 1999年第2期10卷 121-122页

作者： Mei DU Sheng JIN Zhen Quan GUO(college of chemistry and{2. engineering. peking university. 100871)(college of Life Science, peking university, 100871) peking Univ Coll Chem & Mol Engn Beijing 100871 Peoples R China peking Univ Coll Life Sci Beijing 100871 Peoples R China

The monoclonal antibody ID11D7 to carboxypeptidase A (CPA) was prepared. Theinhibitory effect of McAb ID11D7 on the peptidase activity of CPA was measured. The result reflectsthat the McAb ID11D7 can competitively inhibit the peptidase activity of CPA with an apparentinhibitory constant of 6.3 × 10-9M. Based on this work. the McAb ID11D7 can be used as idiotypicantigen to prepare anti-idiotypic catalytic antibody with the peptidase activity similar to CPA.

关键词： Monoclonal antibody carboxypeptidase A (CPA) competitive inhibition peptidaseactivity