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Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cellss

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Cell Research 2002年第2期12卷 143-150页

作者： SHENG JIAN JI, FENG LIU, ER Qiu LI, Yu XIAN ZHUThe National Laboratory of Protein Engineering and Plant Genetic Engineering, college of life sciences, peking university, beijing 100871, china The National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing China

The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth （Plutella xylostella） larvae were killed in both groups with LC50 value of 18.4 μM and 0.70 μM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 μM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 μM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma

关键词： Scorpion toxin AaIT prokaryotic expression cytotoxicity.

Isolation of extracellular CaM-binding proteins from transgenic tobacco seedlings with a magnetic method

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Chinese Science Bulletin 1997年第24期42卷 2081-2084页

作者： GU Xuesong, CHEN Zhangliang and ZHU YuxianThe National Laboratory of Protein Engineering and Plant Genetic Engineering, college of life sciences, peking university, beijing 100871, china The National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing China

USING a magnetic method which was designed for identification of CaMBPs according to theprinciples of affinity chromatography, we were able to isolate 3 CaMBPs with calmodulin(CaM) binding activity from the cell wall fractions of transgenic tobacco. After SDS-PAGEand CaM gel overlay analysis, we found that CaMBPs were retained and the isolation is effi-

关键词： extracellular isolation and identincation CaM-binding protein.

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Structural components of the nuclear body in nuclei of Allium cepa cells

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Cell Research 2001年第1期11卷 68-73页

作者： TAO WEI, CHANG HUI YAN, TAO CAI, SHUI HAO, ZHONG HE ZHAI (college of life sciences, peking university, beijing 100871, china) (Institute of Genetics and Cytology, Northeast Normal university, Changchun Jilin 130024, china) college of life sciences Peking University Beijing China Institute of Genetics and Cytology Northeast Normal University Changchun Jilin China

Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and fUnction are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 μm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level codeined that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.

关键词： Nuclear body structural component ribonucleoproteins nucleolus Allium cepa.

Analysis of Five Differentially Expressed Gene Families in Fast Elongating Cotton Fiber

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Acta Biochimica et Biophysica Sinica 2004年第1期36卷 51-56页

作者： Jian-Xun FENG, Sheng-Jian JI, Yong-Hui SHI, Yu XU, Gang WEI, and Yu-Xian ZHU( National Laboratory of Protein Engineering and Plant Genetic Engineering, college of life sciences, peking university, beijing 100871, china ) National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing 100871 China

Using the suppression subtractive hybridization method, we isolated five gene families, including proline-rich proteins (PRPs), arabinogalactan proteins (AGPs), expansins, tubulins and lipid transfer proteins (LTPs), from fast elongating cotton fiber cells. Expression profile analysis using cDNA array technology showed that most of these gene families were highly expressed during early cotton fiber developmental stages (0-20 days post anthesis, DPA). Many transcripts accumulated over 50-fold in 10 DPA fiber cells than in 0 DPA samples. The entire gene family -AGP, together with 20 individual members in other 4 gene families, are reported in cotton for the first time. Accumulation of cell wall proteins, wall loosening enzymes, microtubules and lipid transfer proteins may contribute directly to the elongation and development of fiber cells.

关键词： cotton fiber cDNA array cell elongation arabinogalactan protein lipid transfer protein

A brief account on the study of the insulin crystal structure In retrospect:Forty years after the determination of insulin’s crystal structure by Chinese scientists

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Science china(life sciences) 2010年第1期53卷 13-15页

作者： WANG Da-Cheng1 & GU XiaoCheng2 1 National Laboratory of Macromolecules,Institute of Biophysics,Chinese Academy of sciences,beijing 100101,china 2 college of life sciences,peking university,beijing 100871,china National Laboratory of Macromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China college of life sciences Peking University Beijing China

"Standards there as high as achieved elsewhere";news delivered to the world by Science in china Approximately forty years ago when china was undergoing a period of great difficulty, Science in china,

关键词： A brief account on the study of the insulin crystal structure In retrospect

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Comparative Study of Apoptosis-related Gene Loci in Human,Mouse and Rat Genomes

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Acta Biochimica et Biophysica Sinica 2005年第5期37卷 341-348页

作者： Yan-Bin YIN Yong ZHANG Peng YU Jing-Chu LUO Ying JIANG Song-Gang LI Center of Bioinformatics, National Laboratory. of Genetic Engineering and Protein Engineering, college of life sciences peking university,beijing 100871, china Center of Bioinformatics National Laboratory of Genetic Engineering and Protein Engineering College of Life Sciences Peking UniversityBeijing 100871 China

Many genes are involved in mammalian cell apoptosis *** apoptosis genes oftencontain characteristic functional domains,and can be classified into at least 15 functional groups,accordingto previous *** an integrated bioinformatics platform for motif or domain search from threepublic mammalian proteomes(International Protein Index database for human,mouse,and rat),we system-atically cataloged all of the proteins involved in mammalian apoptosis *** localizing those proteinsonto the genomes,we obtained a gene locus centric apoptosis gene catalog for human,mouse and *** phylogenetic analysis showed that most of the apoptosis related gene loci are conserved amongthese three ***,about one-third of apoptosis gene loci form gene clusters on mammalchromosomes,and exist in the three species,which indicated that mammalian apoptosis gene orders arealso *** addition,some tandem duplicated gene loci were revealed by comparing gene loci clustersin the three *** data produced in this work were stored in a relational database and may be viewedat http://***/database/***.

关键词： apoptosis gene cluster comparative genomics bioinformatics

Cellular mechanism for spontaneous calcium oscillations in astrocytes

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Acta Pharmacologica Sinica 2006年第7期27卷 861-868页

作者： Tong-fei WANG~2 Chen ZHOU~2 Ai-hui TANG Shi-qiang WANG Zhen CHAI~3 State Key Laboratory of Biomembrane and Membrane Biotechnology,college of life sciences,peking university,beijing 100871,china State Key Laboratory of Biomembrane and Membrane Biotechnology College of Life Sciences Peking University Beijing China

Aim:To determine the Ca2+source and cellular mechanisms of spontaneous Ca2+oscillations in hippocampal ***:The cultured cells were loadedwith Fluo-4 AM,the indicator of intracellular Ca2+,and the dynamic Ca2+tran-sients were visualized with confocal laser-scanning ***:Thespontaneous Ca2+oscillations in astrocytes were observed first in co-culturedhippocampal neurons and *** oscillations were not affected bytetrodotoxin(TTX)treatment and kept up in purity cultured *** Ca2+oscillations were not impacted after blocking the voltage-gatedCa2+channels or ethylenediamine tetraacetic acid(EDTA)bathing,indicating thatintracellular Ca2+elevation was not the result of extracellular Ca2+***,the correlation between the spontaneous Ca2+oscillations and theCa2+store in endoplasmic reticulum(ER)were investigated with *** oscillations were:1)enhanced when cells were exposed to bothlow Na~+(70 mmol/L)and high Ca2+(5 mmol/L)solution,and eliminated completelyby 2 μmol/L thapsigargin,a blocker of sarcoplasmic reticulum Ca2+-ATPase;and2)still robust alter the application with either 50μmol/L ryanodine or 400μmol/Ltetracaine,two specific antagonists of ryanodine receptors,but depressed in adose-dependent manner by 2-APB,an InsP3receptors(InsP3R)***:InsP3R-induced ER Ca2+release is an important cellular mechanismfor the initiation of spontaneous Ca2+oscillation in hippocampal astrocytes.

关键词： hippocampal astrocytes spontaneous Ca2+ oscillations endoplasmic reticulum Ca2+ store InsP3 receptors confocal laser scanning microscope

Expression of rice dwarf phytoreovirus Pns6 and the specificity analysis of its monoclonal antibodies

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Science china(life sciences) 2009年第10期52卷 958-964页

作者： JI Xu, WEI ChunHong & LI Yi peking–Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, the National Laboratory of Protein Engineering and Plant Genetic Engineering, college of life sciences, peking university, beijing 100871, china peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology the National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing China

The genome of rice dwarf phytoreovirus (RDV) is composed of 12 double-stranded RNA segments, of which segment S6 encodes a non-structural protein Pns6 identified as the movement protein. In this report, Pns6 with a 6-histidine tag at the N-terminal was expressed in E. coli after induction under low temperature (18℃) and low concentration (0.4 mmol/L and 0.2 mmol/L) of IPTG, and then purified by Ni-chelated affinity chromatography. Stability analysis indicated that the expressed HisPns6 protein was stable at 37℃ after 24 h treatment. This recombinant protein was then used to make monoclonal antibody. Total 18 hybridoma clones were obtained. The specificity of antibodies was tested by Western blot using native Pns6 extracted from RDV-infected rice leaves, and 15 positive clones were confirmed. Mapping of the antigenic sites of Pns6 using antibodies showed that the most sensitive antigen determinant is located in the C-terminal region (the 296th-509th amino acids) of Pns6, which is confirms bioinformatics analysis.

关键词： rice dwarf virus Pns6 expression monoclonal antibody antigen determinant

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Recent progress in the study of intracellular toxicity of amyloid P peptide in Alzheimer's disease

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Progress in Natural Science:Materials International 2007年第3期 233-236页

作者： ZHANG Yan and YU Longchuan (college of life sciences, peking university, beijing 100871, china)

Amyloidβ(Aβ) deposition is one of the major pathological markers of Alzheimer’s disease (AD). Extracellular Afi toxi-city has been studied for a long time in AD research field. However, controversial data show that extracellular Aβload does not correlate with the dementia levels of AD patients and extracellular Aβonly induces significant cell death at non-physiological high concentrations. With the evolvement of Afi hypothesis, considerable attention has been devoted to the study of intracellular Aβtoxicity recently. Intracellular Aβinduces dramatic cell loss in AD transgenic models and in human primary neurons (at pM concentrations) through p53, Bax and caspase-6 pathways. Here, we review the generation, toxicity and possible pathways of intracellular Aβtoxicity, and discuss the implication and current knowledge of intracellular Aβin neuronal cell loss in neurodegenerative diseases.

关键词： Alzheimer’s disease amyloid P peptide neruonal loss.