25 August 2017, Volume 37 Issue 8
    

  • Select all
    |
  • Molecular Mechanism of Inducing GLC-82 Cells Apoptosis by Ethanol Extract from Wedelia prostrate(Hook.et Arn.) Hemsl
    DAI Li-ting, WU Zhong-nan, HUANG Xiang, YANG Jie, ZENG Hui-lan, WANG Guo-cai, JIANG Jian-wei
    China Biotechnology. 2017, 37(8): 1-7. https://doi.org/10.13523/j.cb.20170801
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Objective:To study the antitumor mechanism of W40, a monomer purified from Wedelia prostrate (Hook.et Arn.) Hemsl. Methods:The effects of W40 on the cell proliferative of GLC-82 cells were detected by MTT assay and colony formation assay. The migratory abilities of GLC-82 cells were observed by wound healing assay. Cell apoptosis was evaluated by Annexin V-FITC/PI staining analysis.The levels of apoptosis-relative proteins and cell proliferation-related proteins, such as Caspase-3, PARP, Stat3 and ERK, were detected by Western blotting. Results:MTT assay showed that W40 had a significant cytotoxic effect on non-small cell lung cancer GLC-82 cells. Colony formation assays showed that W40 significantly inhibited GLC-82 cells proliferation.The migration of GLC-82 cells was inhibited by W40 in a dose-dependent manner. Flow cytometry showed that the apoptotic rate increased gradually in a concentration-dependent manner. W40 down-regulated Stat3 as decreasing p-Stat3 and downstream proteins of Bcl-2 and Mcl-1. At the same time, W40 up-regulated the expression of pro-apoptotic protein Bax, and increased the cleavaged Caspase-9,Caspase-3 and PARP. W40 also down-regulated BRAF/MAPK/ERK signal pathway as decreasing p-BRAF, p-MEK and p-ERK. Conclusions:W40 induced apoptosis by inhibiting BRAF/MAPK/ERK and Stat3 signaling pathways.
  • 3D Hydrogel Compression Model and Effect of Cyclic Compression on Osteoblast Differentiation
    ZHANG Ling-li, TONG Xiao-yang, GUO Jian-min, LEI Le, ZOU Jun
    China Biotechnology. 2017, 37(8): 8-14. https://doi.org/10.13523/j.cb.20170802
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Objective:3D hydrogel cell model was established, and cyclic compressive loading on MC3T3-E1 cell with different intensities, frequencies and durations was applied, in order to research the suitable solution about promoting the osteoblast differentiation with cyclic compression. Methods:Cyclic compressive loading on MC3T3-E1 cell was applied with different intensity, frequency and time. After compressive loading finished, the total RNA extraction from cell-gel constructs were performed and quantified ATF4, ALP, Runx2, Osteocalcin, RANKL and RANK mRNA. Results:RANKL and RANK mRNA expression significantly with different frequencies cyclic compressive loading (P<0.05), and ALP mRNA (P<0.05) and Runx2 mRNA (P<0.01) expression significantly with different intensities and frequencies cyclic compressive loading (P<0.05). Meanwhile, Runx2 mRNA expression with 4h significant higher than 12h (P<0.05), and RANKL mRNA expression with 4h significant lower than 12h (P<0.05). Conclusion:Determine the stress intensity and frequency, 1% intensity, frequency of 0.5 Hz, 4 h of cyclic compression intervention could promote the growth of osteoblasts-like cells in the 3D hydrogel model.
  • Comparison of Signal Peptides for Two Hemicellulase Secretory Expression
    YANG Qing, WANG Bin, WANG Ya-wei, ZHANG Hua-shan, XIONG Hai-rong, ZHANG Li
    China Biotechnology. 2017, 37(8): 15-22. https://doi.org/10.13523/j.cb.20170803
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Xylanase and mannanase are two hemicellulases, which are widely used in many fields.To improve the expression of thermostable xylanase DSB and thermostable mannanase ManA in Pichia pastoris, three endogenous signal peptides of Pichia pastoris(Scw11, Dse4 and Exg1) were chosed. Their capability to mediate the secretion of DSB and ManA with that of the Saccharomyces cerevisiae α-factor were compared. In shake-flask cultivation, three endogenous signal peptides and α-factor efficiently mediated the secretion of DSB and ManA, but the secretion efficiency has obvious difference. As for DSB,the expression efficiency of α-factor was much higher than three endogenous signal peptides. But as for ManA, the expression efficiency of Dse4 was equal to α-factor and much higher than Scw11 and Exg1. Therefore,α-factoris the most efficient signal peptide for DSB expression and Dse4 or α-factor are the most efficient signal peptide for ManA expression in Pichia pastoris X33.Moreover,the intracellular activities of DSB and ManA by α-factor are higher than Scw11, Dse4 and Exg1, and the intracellular activity of ManA was higher than DSB (the molecular weight of ManA was larger than DSB).Thus, when ManA were expressed in Pichia pastoris, different signal peptide, such as Dse4, could be used for improving the secretion efficiency.A basis for identifying more available signal peptides and screening for the optimal signal peptide for the target protein was provided.
  • Studies on the 3-Ketosteriod-1-Dehydrogenation of Steroid Hormone by Cellular lysates of Mycobacterium
    QIN Meng-fei, SUN Hong, SONG Hao
    China Biotechnology. 2017, 37(8): 23-30. https://doi.org/10.13523/j.cb.20170804
    Abstract ( ) Download PDF ( )   Knowledge map   Save

    9β, 11β-Epoxypregn-4-ene-17α, 21-diol-3, 20-dione 21-acetate (Ⅰ) is a substrate for the production of 9β, 11β-Epoxypregn-1, 4-diene-17α, 21-diol-3, 20-dione (Ⅳ), which is a key precursor for the production of many 9-fluoro-substituted corticosteroid hormones. By comparing whole cells catalysis and cellular lysates conversion, it was found that whole cells of Mycobacterium sp. MS136 could only convertⅠto 9β, 11β-Epoxypregn-4-ene-17α, 21-diol-3, 20-dione (Ⅱ), and Ⅰ can be effectively converted toⅣ by cellular lysates.The reaction order is that Ⅰ is spontaneously hydrolyzed to Ⅱ and Ⅱundergoes C1, 2-dehydrogenation reaction toⅣ.In order to improve the productivity of Ⅳ, the key genes kstD, kstD3 and kstDM encoding C1, 2-dehydrogenase (KSTD)were overexpressed in Mycobacterium sp. MS136 to enhance the C1, 2-dehydrogenation reaction rate, and the results showed that 1 g/L substrate Ⅰ can be converted by recombinant strain MS136-kstDM cellular lysates at pH 7.0, the productivity of Ⅳreached 78.4% after 45 h, which is 38.9% higher than original strain.The reaction rate is enhanced by optimizing the pH, and the results showed that 1 g/L substrate (Ⅰ) can be converted by recombinant strain MS136-kstDM cellular lysates at pH 7.5, the productivity of Ⅳreached 92.8% after 45 h, which was 63.4% higher than original strain.

  • Characteristics and Kinetic Study of 2-Hydroxypyridine Degradation by a Novel Bacterium Arthrobacter sp. 2PR
    HU Chun-Hui, XU Qing, YU Hao
    China Biotechnology. 2017, 37(8): 31-38. https://doi.org/10.13523/j.cb.20170805
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A novel strain, which could use 2-hydroxypyridine (2HP) as the sole source of carbon, nitrogen, and energy, was isolated from petroleum-contaminated soil at the Liaohe estuarine wetland. Strain 2PR was identified as Arthrobacter based on the morphology and 16S rRNA gene sequence. The optimum growth and degradation condition upon 2PR is 30℃ and pH 7.0, respectively. Under this condition, 2HP degradation rate were 97.34%, 94.95%, 94.48% and 89.21% with 2, 4, 6 and 8 mg/ml initial concentration of 2HP at 42, 96, 120 and 156 h, respectively. Strain growth and 2HP degradation kinetics studies indicated that the strain followed Logisitic model, which could provide a theoretical and technical reference for the biodegradation of 2HP. The color of strain 2PR culture upon 2HP-MSN changed from colorless to blue, and then turned to brown. The blue pigment, which was observed at the culture of strain 2PR, was identified as 4,5,4',5'-tetrahydroxy-3,3'-diazadiphenoquinone-(2,2') by high performance liquid chromatography (HPLC) and high-performance liquid chromatography-mass spectrometry (LC-MS) analysis. The LC-MS signal with m/z=249.1 was observed in resting cells reaction sample with 2HP as the substrate. The degradation of 2HP might be achieved by a dioxygenase to produce 2,3,6-trihydroxypyridine, which could transformed to the blue pigment spontaneously, and then 2,3,6-trihydroxypyridine was converted with an pyridine-ring cleavage reaction. Among all the reported strains, strain 2PR has the strongest tolerance and the highest 2HP degradation efficiency at present. The strain has a promising application potential for 2HP waste treatment.
  • Establishment and Phenotype Analysis of SHBG Knockout Mouse Model
    SUN Yi-ping, WANG Yue, JIN Zhen, WANG Xiao-yan, SUN Lei, ZHANG Xuan, FENG Chong, ZHOU Xiao-hua
    China Biotechnology. 2017, 37(8): 39-45. https://doi.org/10.13523/j.cb.20170806
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Objective:To generate sex hormone binding globulin(SHBG)conditional knockout mice model. In order to investigate the physiological function of SHBG in vivo and to provide experimental means for the study of the relationship between SHBG and gestational diabetes mellitus. Methods:The mouse genomic DNA sequence of SHBG was verified through bioinformatic analysis. According to the SHBG genomic DNA sequence, the gene targeting and knockout vector were constructed. Transfection of the vectors to ES cells by electroporation was performed according to common protocol. Positive ES cells were screened and identified by PCR. Therefore, the dual selected ES cells were microinjected into blastula, then blastula transplantations into the host mice. The chimeric mice were mated with C57BL/6J mice,and the Flox mice were obtained after screening. The Flox mice were hybridized with EⅡA-Cre transgenic mice,and the progeny of the SHBG gene knockout (SHBG-/-) mice were obtained by autocopuation for several times. Results:Several Flox homozygous mice and SHBG gene knockout mice were successfully obtained. Compared with control mice,homozygous mice of SHBG gene knockout were well developed and had reproductive ability. The growth and development of SHBG knockout mice were not significantly different from that of wild type mice.Conclusion:Homozygous mice model of SHBG gene knockout was successfully established,which laid the foundation for further study of the role of SHBG in the gestational diabetes. The SHBG gene knockout mouse model was successfully established and the preliminary phenotypic analysis was performed, which laid the foundation for further study on the role of SHBG in gestational diabetes mellitus. SHBG gene knockout mice were normal in appearance. Due to the limited number of samples and many unknown biological characteristics of gene knockout mice, it needs further study.
  • Construction and Characterization of Electrochemical Biosensor based on Endotoxin Aptameer
    YI Yu, WANG Min-jun, MEI Jian-feng, CHEN Jian-shu, ZHANG Yan-lu, YING Guo-qing
    China Biotechnology. 2017, 37(8): 46-50. https://doi.org/10.13523/j.cb.20170807
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A biosensor was constructed to detect the endotoxin.The amine-terminated aptamer was immobilized on the gold electrode surface covered in advance with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA). The modification of the gold electrode was confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that MPA assembly time at 6 h in the gold electrode surface to form a stable self-assembled monolayer.The biosensor has a good linear relationship with concentration of endotoxin in the range of 0.001~0.1 EU/ml, it is possible to be applied for quality control in the actual biological sample.
  • Production of Restriction Endonuclease Not I Utilizing CpG DNA Methylase M.Sss I Co-expression Vector
    WANG Pei, CHEN Kai, GAO Song
    China Biotechnology. 2017, 37(8): 51-58. https://doi.org/10.13523/j.cb.20170808
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Restriction endonucleases are important molecular biology tools for DNA recombination. Because of the cleavage of DNA, their recombinant expression is difficult with low yields and complicated purification processes. In commercial productions, the technology that uses specific methylases to protect host DNA from digestion of the expressed restriction enzymes was cumbersome and practically limited. For solving this problem the expression of restriction enzyme Not I was performed by using the DNA methylase M.Sss I derived from Spiroplasma sp. MQ1 which specifically kept CpG sequence methylated. The methylated DNA was protected from the cutting of Not I whose recognition sequence contained CpG. The gene of methylase M.Sss I was introduced into Escherichia coli ER2566 and constitutively expressed, resulting in the CpG methylation pattern of the host DNA. Restriction enzyme Not I was successfully expressed in this E. coli strain. Furthermore, by adding a purification tag to one terminus of the enzyme, recombinant Not I was prepared as a highly purified and active product through two simple Ni-affinity and anion exchange chromatography steps. This expression system can be applied for the preparation of a series of restriction enzymes with CpG in their recognition sequences.
  • High Throughput Screening Method and Application for L-glutamate Specific Aminotransferase
    HE Lin-wei, LIU Zhang-min, FENG Yan, CUI Li
    China Biotechnology. 2017, 37(8): 59-65. https://doi.org/10.13523/j.cb.20170809
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Objective:The aim is to establish L-glutamate specific aminotransferase-L-glutamate dehydrogenase coupling 96-well high throughput screening method, which is applied to molecular evolution of aminotransferase WecE from E.coli. Methods:An optical assay for aminotransferase catalytic activity based on aminotransferase-glutamate dehydrogenase coupling system is established by optimization of coupling enzyme loading, signal molecule NADH concentration and coupling time. Mutants library of WecE is obtained by site-directed saturation mutagenesis. Positive mutants can be screened out through 96-well preliminary screening and flask second screening. Results:The target transamination reaction is coupled with L-glutamate dehydrogenase indicative reaction system which consists of 0.5 U/ml enzyme loading and 0.4 mmol/L NADH. A positive mutant Y321F whose catalytic activity increases 3.4 fold compared to that of wild type is screened out in Tyr 321 saturation mutagenesis library of WecE. Conclusion:An accurate high throughput screening method with weak background interference is established. It offers feasible solution for molecular evolution of L-glutamate specific aminotransferase.
  • Research Progress of Bacterial Lux Bioluminescence Reporter System
    CUI Qing-yu, WANG Ming-yu, XU Hai
    China Biotechnology. 2017, 37(8): 66-71. https://doi.org/10.13523/j.cb.20170810
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Lux reporter plays an important role in molecular biology, clinical microbiology and biochemical detection, owing to its high sensitivity, fast reaction and convenience. Here the component, types and characteristics of lux reporter system were introduced. Moreover, the recent advance of its application in environment detection, food safety, new drug discovery and tumor locating were reviewed.
  • Advances in Optimization of Hyaluronic Acid Production by Genetic Engineering Technology
    GAO Jiao-jiao, YANG Shu-lin
    China Biotechnology. 2017, 37(8): 72-77. https://doi.org/10.13523/j.cb.20170811
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Hyaluronic acid is a linear acid mucopolysaccharide composed of repeating disaccharide glucuronic acid and N-acetyl-glucosamine units, which is widely used in medicine, cosmetics, food and other fields. Traditional studies have made significant achievements in improving the production of hyaluronic acid by optimizing the fermentation parameters, but have reached the upper limit, and the natural strains have the increasing disadvantages of high cost of fermentation medium and pathogenicity. With the rapid development of molecular biology technology and the continuous research on the genes related to hyaluronic acid synthesis, the research focus has gradually shifted to the use of genetic engineering technology to construct high yield, safe and specific molecular weight hyaluronan genetically engineered strains. Here the strategies and research progress of genetic engineering for the production of hyaluronic acid were reviewed.
  • The Application of Graphene and Derivatives in Orthopedics
    JIAO Yang, LIU Heng, Talatibaike·Maimaitijuma, CAO Yong-ping
    China Biotechnology. 2017, 37(8): 78-83. https://doi.org/10.13523/j.cb.20170812
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Graphene and its derivatives have unique physical, chemical and biological properties, such as antibacterial property, promoting osteogenesis, increasing the wear resistance of composite materials, etc. It has broad application prospects in biomedicine and tissue engineering. The application and research progress of graphene and its derivatives in orthopedics were introduced, in order to provide theoretical basis for the future clinical and fundamental research.
  • Heterologous Expression of Nanobodies:a Recent Progress
    LI Dan, HUANG He
    China Biotechnology. 2017, 37(8): 84-95. https://doi.org/10.13523/j.cb.20170813
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Heavy chain antibodies(HcAb) without light chains are naturally produced by camelids. The single domain antigen-binding fragment of HcAb is referred to as VHH or nanobody (Nb), which is the smallest antigen-binding entity at present. Several characteristics such as low molecular weight, high stability, and low immunogenicity make the use of nanobodies superior to the conventional antibodies. Currently, nanobodies are highly valuable antibodies for various applications, including fundamental research, diagnostics, and therapeutics. A variety of nanobodies are investigated in clinical researches. The recent progresses of heterologous expression of nanobodies in seven expression systems, including Gram-negative and positive bacteria, yeasts, filamentous fungi, insect cells, mammalian cells and plant cells were focused on, and the expression systems, hosts, characteristics of vectors, construction of vectors and yield of nanobodies were summarized. The strategies to increase the yield of nanobodies are discussed from molecular level, expression level and rational design.
  • Mechanism and Applications of Bio-mineralization Induced by Sporosarcina pasteurii and Related Microorganisms
    WU Yang, LIAN Ji-jian, YAN Yue, QI Hao
    China Biotechnology. 2017, 37(8): 96-103. https://doi.org/10.13523/j.cb.20170814
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As known so far, Sporosarcina pasteurii, or formally termed as Bacillus pasteurii, was considered as one of the most efficient biosystem which is capable of inducing biological mineralization through breaking down urea. Taking advantage of the ‘super power’ of bio-mineralization, Sporosarcina pasteurii has been successfully utilized in application of solidifying sand as a novel biological construction technology, termed as ‘bio-cementation’. Due to the nature of Sporosarcina pasteurii isolated from soil, non-pathogenicity has been observed, it was considered as a very environmentally friendly method. Recently, Sporosarcina pasteurii has been further applied into fields including environmental improvement and biomedicine. However, the mechanism under the strong Sporosarcina pasteurii mediated bio-mineralization is still not well understood. Here, the knowledge and the up-to-date studies about the biological mechanism of Sporosarcina pasteurii mediated bio-mineralization, and the utilization in construction, environment, and biomedicine are reviewed.
  • Progress on Function and Biosynthesis of Benzoxazinoids
    GAO Hong-jiang, LI Sheng-yan, WANG Hai, LIN Feng, ZHANG Chun-yu, LANG Zhi-hong
    China Biotechnology. 2017, 37(8): 104-109. https://doi.org/10.13523/j.cb.20170815
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Benzoxazinoids(BXs) are important secondary metabolites in plants.There has been a wide range of attention and research of them because of their role in defensive and allelopathy.With the development of genomics and molecular biology, the BXs biosynthesis and other molecular areas research has made great progress.The BXs profile, the function of BXs, the genetic basis of BXs biosynthesis and expression regulation were briefly introduced.
  • Revision of the General Policies of Nomenclature for Biological Products in China
    GUO Zhong-ping, XU Li
    China Biotechnology. 2017, 37(8): 110-118. https://doi.org/10.13523/j.cb.20170816
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    General Policies of Nomenclature for Biological Products in China were studied, aimed at establishing and perfecting the system of Chinese approved biologic name. By means of analysis of the current situation and existing problems of nomenclature for biological products and the development trend of new biotherapeutics. It is sufficiently studied on the existing leading international drug generic naming system,and the specific suggestions on revision of the General Policies of Nomenclature for Biological Products in China based on the naming principles of WHO INN and Chinese language recognition were put forward.
  • Comparison of Regulation on GM Crops Cultivation Management in USA and China
    LIU Xu-xia, ZHANG Nan
    China Biotechnology. 2017, 37(8): 119-127. https://doi.org/10.13523/j.cb.20170817
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The proposal to promote the commercialization of new insect-resistant GM cotton, GM corn and other major products in "13th Five Year Plan on National Science and Technology Innovation ", has put forward a test to the government's ability to manage GM crops cultivation. Only a few species of GM crops, not including food crops, have been commercialized in China, we lack experience in GM crops cultivation management. Taking USA, where the farmers cultivate huge areas of GM crops, as a comparison object, the examination and approval procedures before cultivation, GM crop growers' obligation of the management, the methods to reduce mingling of GM crops and non-GM crops are compared. And concludes that the differences in legal status of GM crops, the intellectual property regime and labeling regulation, the ability of relative stakeholders to implement segregation measures and bear loss lead to different regulation on GM crops cultivation management in USA and China. The government combine the domestic current situation of the agricultural environment in our country, and focus on substantial risk in the safety management of GM crops in cultivation management is advised. The competent department of agriculture, researchers and seed traders should work together to help guide growers to avoid the economic disputes due to mingling and reduce the impact on the ecological environment.
Office Online
AnnouncementMore...
Latest publication More...
Links More...
Wechat
主管：中国科学院 　主办：中国科学院文献情报中心 　中国生物技术发展中心 　中国生物工程学会
Copyright © China Biotechnology, All Rights Reserved.
Powered by Beijing Magtech Co. Ltd.