25 September 2009, Volume 29 Issue 09
    

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  • China Biotechnology. 2009, 29(09): 0-0.
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    Objective:To obtain the human single chain antibody (scFv) against fusion protein of Respiratory Syncytial Virus. Methods:A na?ve library of phage display human scFv, genes of which were derived from peripheral blood lymphocytes (PBLs) of 10 healthy donors, was constructed and panned by F of RSV to select specific anti-RSV F scFv. After 5 rounds of panning, the activity of individual clone was examined by ELISA. The genes of positive clones were sequenced. Soluble scFv was prepared through infecting E.coli HB2151 with one of the positivephage clones. Results:After the panning, scFvs from 18 clones can bind F specifically by ELISA. DNA sequence analysis of the clone E4 with the highest OD indicates that the variable region gene of the clone is highly homologous with human immunoglobulin gene family. The expression of scFv E4 has been confirmed by Western and Dot blots. Conclusion:The specific human anti-RSV F scFv has been prepared successfully by exploiting phage antibody library.
  • China Biotechnology. 2009, 29(09): 0-0.
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    β-lactamase inhibitor research is popular for its potential onβ-Lactam antibiotics resistant strain. A β-lactamase binding peptide SIPIS04-01 was obtained by the yeast two-hybid system. In vitro assay showed that it can inhibit the β-lactamase activity. In order to improve the expression level of the recombinant peptide, a two-copy expression plasmid pYG563 was constructed by random orientation tandem repeat method After codon modification, this two-copy plasmid was successfully expressed and the product was increased by 48.4% than that of one-copy plasmid. Purified peptide showed inhibitory activity against TEM-1 β-lactamase in vitro and the inhhibitory constant Ki was measured.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Straw contains large quantities of lignocelluloses that the structural is stability and hardly degraded. The influence of the different mixtures of five strains that can degrade lignocelluloses were studied using mixture design. Regression model on microorganism composition and degrading rate of lignocelluloses and content of reducing sugar was established. The predictable degrading rate of cellulose reached the maximum, 35.75%, the maxim predictable degrading rate of lignin was 27%, the most predictable production of reducing sugar was 3.39mg/g.Based on these response values satisfied all expectation were optimized, and the most excellent combinations of Bacillus Subtilis, Bacillus Licheniformis, Canadian krusei, Trametes versicolor, Phaerochaete chrysosporium were 12.1%,10%, 27.2%, 10.6%, and 40%, respectively.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Rex-1 and Oct4 are transcription factors which are specifically expressed in pluripotent cells. However, the molecular mechanisms of Rex-1 and Oct4 regulating the pluripotency and differentiation of embryonic stem cells (ES cells) are not very clear. The interaction between Rex-1 and Oct4 is studied here. Rex-1 and Oct4 co-localize in the nucleus and have direct protein interaction. Rex-1 inhibits the transcriptional activity of Oct4 through this interaction.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Neuroglobin (NGB), widely and specially expressed in neurons of various vertebrates, was reported to be a scavenger of reactive oxygen species and/or a stress-responsive sensor for signal transduction for neuroprotection of hypoxic and ischemic insults as some researches had been described. However, the underlying mechanism remained unknown. Obviously, it would be played an important role for preparation of neuroglobin in studying its function. To address it, the human neuroglobin cDNA fragment was amplified by RT-PCR from human fetus brain and cloned into the prokaryotic expression vector pBV220, and then transformed into E. coli HB101 cells for expression. The expressed protein was purified by gel filtration and anion exchange column followed with SDS-PAGE and Western blot identification, and then desalting by Sephadex G-25 medium. The prepared neuroglobin was further identification by mass spectrometry and N-terminal amino acid sequencing analysis. In conclusion, the neuroglobin was not only expressed in soluble form with high-efficiency in E. coli, but also could be easily purified with two steps. The successful expression and purification of the recombinant human neuroglobin will advance the study of neuroglobin either for the neuroprotective function or deciphering the underlying mechanism of hypoxic/ischemic insults.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Abstract:Objective: Aldose reductase gene, involved in the pathogenesis of diabetic complications, was recombinated with an adeno associated virus vector pSNAV2.0, and transfected into human embryonic kidney 293 (HEK 293) cells. The gene engineering produced AR would be used as the target protein to screen aldose reductase inhibitors. Restriction endonuclease digestion and ligation procedures were performed to construct the AR expression plasmid vector pSNAV-hAR. Methods: After confirmation the recombinant plasmid by PCR, restriction endonuclease digestion, and DNA sequencing, pSNAV-hAR was transfected into HEK293 cells. Results: The results of a series of analysis including AR activity assay, Western blot and immunofluorescence analysis shown the expressed protein mediated by the adeno associated virus vector transfecting HEK 293 cells, was functional AR. The traditional aldose reductase inhibitors, Sobinil and Zopolrestat, were used to test and verify the constructed cell model. Conclusion: The established AR expression model can be used in mechanismresearch of activation of polyol pathway on diabetic complications and screening potential aldose reductase inhibitors. Based on previous work, the characteristics of AR expression in the yeast cells, Saccharomyces cerevisiae, and human embryonic kidney 293 cells were introduced. Three kinds of AR activity assay methods and matters need attention were discussed as well.
  • Song-Shan TANG
    China Biotechnology. 2009, 29(09): 0-0.
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    AIM: Growth hormone releasing hormone (GHRH) is one of the hypothalamus hormones. Because of its potential applications in agriculture and human medicine, an analog with high GHRH activity and prolonged half-life has been looked for. Methods: By using the fusion protein expression protocol with unique acid labile linker Asp-Pro, the Pro-hGHRH(1-44)-Gly-Gly-Cys peptide was obtained. The peptide was purified to homogeneity by means of cell disruption, washing of inclusion body, ethanol fraction precipitation, acid hydrolysis, SP-Sephadex C-25 and Sephadex G-10 column chromatography. Results: The peptide molecular weight of 5,373 Da measured by EIS-MS is coincident with the actual values and its purity was determined by SDS-PAGE. The peptide at 0.1-10 μg/ml increased GH releases both from human pituitary and from rat pituitary. The rat pituitary GH-releasing activity increased in a dose-dependent manner. Compared with the standard hGHRH(1-40), the two GHRH analogs had higher rGH-releasing activities. The standard hGHRH(1-40) at 0.01-2.0 μg/ml showed no measured rat GH release. The activity comparisons showed that the rat pituitary GH-releasing activity of the Pro-GHRH(1-44)Gly-Gly-Cys peptide was not more than that of the Pro-hGHRH(1-44) peptide, whereas the human pituitary GH-releasing activity of the Pro-GHRH(1-44)-Gly-Gly-Cys peptide was far less than that of the Pro-hGHRH(1-44) peptide although there was not significant between them. Conclusion: The activity results showed that they had good GH-releasing activity, function-selecting and species specificity.
  • China Biotechnology. 2009, 29(09): 0-0.
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    The bioconversion of lignocellulosic materials for organic acid had great meaning to both economic and social benefit, owning to its renewable character, abundance and low price. This article extensively reviewed the xylose metabolic pathway of Rhizopus sp., discussed kinds of fermentation strategies to product organic acid(such as lactic acid, fumaric acid) from lignocellulosic, and pointed out the key to product organic acid from lignocellulosic was the efficient utilization of xylose.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Phage Display Technology has been developed as a powerful tool for selecting polypeptides or proteins with desired biological and physicochemical properties from huge random peptide libraries. Fragments of foreign peptides or proteins are expressed as fused proteins displayed on the phage surface, so that they can interact with their ligands to mimic selection of specific molecular epitopes, thus providing an efficient high-throughput screening system. Phage display has been used to allow rapid identification of peptide ligands for a variety of target molecules by an in vitro selection process called “panning”. Phage display techniques can be widely exploited to construct tumor-associated antibody libraries, select polypeptides tumor-associated antigen, investigate antigen epitope and design vaccines and medicine, and are used especially as a tool for the diagnosis and treatment of tumor, gene therapy and tumor cell signal transduction research. Recent applications and advanced developments of phage display in cancer research are discussed in this article for the further reference to investigators.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Fibroblast growth factor 21(FGF21)is a novel fatty metabolic regulator. FGF-21 mRNA is most abundantly expressed in the liver. FGF21 can stimulate lipolysis in white adipose tissue and ketogenesis in liver,stimulate glucose uptake in adipocytes,increase insulin level,and delay the development of adenomas. We also find that the development of FGF-21 for the treatment of diabetes and other metabolic diseases will give us the foundation for further study.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Biodegradation of naphthalene has been greatly concerned due to its economic, free –pollution and its fine effect. The development of biodegradation of naphthalene from the following areas including the screening of strain, the development of different kinds of biodegradation pathway, the application status of surfactant, the immobilization technology of cell and organic solvent used in the biodegradation of naphthalene, are reviewed, analyzed the questions ,and its development trends are forecasted.
  • China Biotechnology. 2009, 29(09): 0.
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    This experiment was based on a full-length SAMDC sequence from the drought stress induced cDNA library of Cleistogenes songorica. Two methods, absolute quantificatin and relative quantification, were used to analyze the gene expression under different tissue and drought stress treatment by real-time quantitaive PCR experiments and were compared each other, while CsSAMDC gene was used as a case. Leaves and roots tissue were sampled from the plants at 0, 4, 6, 8, and 10 d of drought stress and 1, and 4 d after rewatering. The 2-△△CT method was used to analyze the relative changes in gene expression from quantitative real-time PCR experiments. A standard curve was generated by the purified plasmid DNA. The primer concentration in the realtime PCR was optimized. All absolute quatification data were normalized by the normalization factor from the most stable house-keeping genes in C. songorica. Relative quantification results using 2 -△△CT method showed that CsSAMDC transcripts increased 5.93±0.71 fold in roots, down regulated 0.62±0.13 fold in leaves, under drought stress. Absolute quantification results showed that CsSAMDC transcripts up-regulated in roots significantly under drought stress as long as 8 to 10 days after drought stress, while down-regulated in both roots and leaves after drought stress within 6 days and 1 to 4 days after rewatering, compared with control. CsSAMDC transcipt showed similar tendency of gene expression compared by using relative and absolute quantification methods.
  • China Biotechnology. 2009, 29(09): 0-0.
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    The method of Dot-ELISA for detecting GPV antibody was established with recombinant prokaryotic expressed peptide of VP1-VP3 non-repeated nucleotide sequences of GPV capsid protein in this test. The coating concentration of Dot-ELISA detecting antigen was 700ng. The optimum dilution of rabbit anti-goose IgG-HRP antibody and detected serum were 1:200 and 1:400 respectively. The positive rate of detected GPV serum antibody was 100%, and the other one of the chicken anti-GPV-VP3 gene recombinant poutry poxvirus serum antibody was 0%.
  • China Biotechnology. 2009, 29(09): 0-0.
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  • China Biotechnology. 2009, 29(09): 0-0.
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    To search for novel HBV preS1-interacting proteins on HepG2 cell membrane, preS1 protein was recombined with GST tag and GST pull down assay was employed to detection of preS1 domain cellular binding protein, using the precleared lysate of biotinylated HepG2 cells as a source of receptor molecules. Our results showed that an approximately 110-kDa protein (p110) was detected to bind to preS1. Tissue distribution analysis further indicated that p110 binding is restricted to human hepatocytes. The data demonstrated that p110 is a binding protein to preS1 on HepG2 cell membrane.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Abstract:Different mechanisms in utilization of various monosaccharides by microorganism (especially G/F discrepancy) were studied. Transportation and phosphorylation are considered to be key factors of this discrepancy. By locating relative genes or operons, genetic modification of industrial microbe could be performed to help further develop multiple biomass energy resource with un-glucosyl group, which is very meaningful to the transformation of energy pattern as well as sustainable development.
  • China Biotechnology. 2009, 29(09): 0-0.
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    By exploring the different components of the lysis buffer and optimize the 2-DE conditions, established the best proteomics technical system for Populus euphratica’s heteromorphic leaves, while take the heteromorphic leaves in the same blanche as the test materials to find differences between the protein expressions of the leaves. It showed that the lysis solution which containing 2mmol/L thiourea,7mmol/L urea, 2% CHAPS,60mmol/L DTT and 0.2% IPG buffer could dissolve the protein better. Through tandem mass spectrum, the results show that heteromorphic leaves are different in photosynthesis and respiration. This research offered valuable informations for understanding the molecular mechanism during leaves development and elucidating the mechanism of the eco-adaptability of Populus euphratica.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Genetic engineering is a powerful tool in Panax ginseng breeding. Genetic transformation and plant regeneration are the key steps involved in genetic engineering of Panax ginseng. Although P. ginseng is recalcitrant to genetic transformation, up to date, substantial advances have been made in genetic transformation and plant regeneration of P. ginseng. This paper is concerned with the recent progresses in genetic transformation and plant regeneration of P. ginseng. Additionally, problems that are present in genetic engineering of P. ginseng were also discussed in this review.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Nature is abundant of protein scaffolds. By selecting suitable protein scaffold, display and screening methods, the rational and constrained random peptide library(RPL) can be constructed and used for selection. Compared with the non-constrained RPL, it offered more opportunities for obtaining novel protein structures and more higher affinity ligands against the target molecules. At present, the protein scaffold constrained RPLs have been shown great potential in applications such as target selection, basic research, clinical diagnosis, medical therapy and so on. This review systematically introduced the structure bases, classification and construction of constrained RPL based on scaffolds, as well the recent great advances of application in selection against target molecules with S-S constrained scaffolds, antibodies, Zinc finger protein, Z domain, FN3 domain as important examples.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Microbial lipases are important industrial biocatalysts with the character of stereoselectivity, site selectivity and high catalytic activity with few side effects. They have been used widely in many industrial and agricultural fields. The technology of protein engineering has been successfully applied to improve the activity and stability of microbial lipases, which will raise the competitive capacity of microbial lipase preparations and enlarge theirs application fields. This review will survey the strategies, the problems and the prospects of protein engineering technology which have been applied to modify the microbial lipases.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Cytoplast and microprotoplast are main subprotoplasts that can play an important role in plant genetic improvement. The present review highlights the advancements in isolation and fusion of plant subprotoplast, and some suggestions and prospects are proposed for the future studies.
  • China Biotechnology. 2009, 29(09): 0-0.
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    In this experiment, plant expression carrier containing TaDREB has constructed in plasmid pBIR1. Aloe stems were used as explants for gene transformation mediated by Agrobaterium. Infected tissues were selected using G418 to generated transformants. 58 resistant plantlets were obtained from the infected explants screened by G418. The designed primers according to the selective gene nptII and the target gene of TaDREB were used for analysis all of the G418 resistant plantlets. PCR results demonstrated that TaDREB were successful transferred into aloe genomic with the transformation efficiency of 0.22%. The transgenic aloe plants were treated under 4℃ for two weeks and -20℃ for 30min.The analysis showed that the leaves of negative plants appear severe evidence of freeze injury with brown, withered and translucent, while the positive plants appear good growing condition. The isozyme patterns such as peroxidase (POD) and superoxide dismutase (SOD)of transgenic plants which are stressed 14 days under low temperature are analyzed by polyacrylamide gel electrophoresis. The results indicated that the trend of SOD and POD activities of transgenic plants are down-up-up-up, and that of non-transgenic plants are down-up-down-down. The average value of relative electrical conductivity in positive plants was 0.462 which was lower than 0.685 in the negative plants. It is supposed that transformation of this kind of gene could improve the resistant ability of aloe.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Little is known about the non-structural protein 6 (NSP6) of rotavirus. This report describes expression of the NSP6 of a group A human rotavirus strain TB-Chen in bacteria, and its immunological properties and cellular distribution. The results showed that the recombinant NSP6 (rNSP6) was expressed in high efficiency without any other proteins fused (possesses about 34.2% of total bacterial proteins). rNSP6 elicited mono-specific antibodies in immunized guinea pigs and the antibodies could react with the rNSP6 itself and the viral NSP6 proteins synthesized in SA11- or Wa-infected MA104 cells in Western blot and immunofluoresence assay. The NSP6 distributed evenly in the cytoplasm mainly around the nucleus of virus-infected cells, no viroplasm-like gathering observed; the top amount of NSP6 synthesized in SA11- or Wa-infected cells could be detected at 12h after infection. This is the first report about the high expression of entire NSP6 (without any other proteins fused) in prokaryotic expression system and detection of NSP6 synthesis in virus infected cells by immunofluorescence assay. These results are important to understand the structure, biological properties and further application of the NSP6.
  • China Biotechnology. 2009, 29(09): 0-0.
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    Hepatitis B virus X (HBx) was a regulatory protein and it was coden by hepatitis B virus (HBV) genome. Serum HBx quantitative detection may be helpful for HBV, hepatocirrhosis, and hepatoma diagnosis. A HBx chemiluminesscence quantitative assay kit was produced following the recombinant HBx antigen expressed in E.Coli and the HBx monoclonal antibodies selected from HBx antigen immunizing mice. The sensibility, specificity and other characteristics of the HBx quantitative assay kit were analyzed. The purity of the recombinant HBx protein was ≥94%. Two of six monoclonal antibodies were selected and used for bait and detect antibody. The sensibility of the HBx quantitative assay kit is 0.1ng/ml, the linearity range of it is 0.5-600ng/ml. No coss-reactions to GLB, lipoprotein, HGB, HBc, HBe, HBs or HBV preS2 were observed. The addition accuracy was between 98.7%-105.7%, and the dilution accuracy was between 95.4%-104.5%. CV (within batch) ≤2.9, CV (batch to batch) ≤6.5. After keep in 37℃ for 4 days, the technical datas were almost same as keeping in 4℃. The HBx quantitative assay kit was use to detecte the HBx in 75 chronic HBV, 20 acute HBV, 25 hepatocirrhosis, 30 hepatoma patients’ serum and 180 healthy people’s serum. More than 55% chronic HBV patients, 68% hepatocirrhosis patients and more than 70% hepatoma patients can be detected. The higher grade of hepatocirrhosis patients classification it was, the higher concentration of the serum HBx was being. All the results show that the HBx chemiluminesscence assay kit we developed can not only be used for serum HBx quantitative detection, but also be used for the relationship between HBx and the hepatoma or the hepatocirrhosis study.