• Title/Summary/Keyword: E. coli system

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Mutagenicity of Lithium Carbonate Assessed by Bacterial Reverse Mutation(Ames) Test (미생물복귀돌연변이(Ames)시험을 통한 탄산리튬의 변이원성 고찰)

  • Rim, Kyung-Taek;Kim, Soo-Jin
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.24 no.3
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    • pp.330-335
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    • 2014
  • Objectives: To evaluate the mutagenicity of lithium carbonate, a bacterial reverse mutation(Ames) test was carried out using four strains of S. typhimurium(TA1535; TA1537; TA98; and TA100) and one strain of E. coli(WP2uvrA). Materials: This was carried out in a dose range from 312.5 to $5,000{\mu}g/plate$ in triplicate with and without S9 activation, which is the most commonly used metabolic activation system supplemented by a post-mitochondrial fraction prepared from the livers of rodents treated with enzyme-inducing agents such as Aroclor 1254 or a combination of phenobarbitone and ${\beta}$-naphthoflavone. Results: No significant increases in the number of revertants were observed under the conditions examined in this study. Conclusions: Based on the above observations, it can be concluded that lithium carbonate has no mutagenic activity. Despite the results, it can have an effect by inducing acute oral toxicity, eye irritation and acute aquatic toxicity. Based on this study, we suggest that future studies should be directed toward chronic, carcinogenic testing and other related areas.

Safety Evaluation of Chrysanthemum indicum L. Flower Oil by Assessing Acute Oral Toxicity, Micronucleus Abnormalities, and Mutagenicity

  • Hwang, Eun-Sun;Kim, Gun-Hee
    • Preventive Nutrition and Food Science
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    • v.18 no.2
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    • pp.111-116
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    • 2013
  • Chrysanthemum indicum is widely used to treat immune-related and infectious disorders in East Asia. C. indicum flower oil contains 1,8-cineole, germacrene D, camphor, ${\alpha}$-cadinol, camphene, pinocarvone, ${\beta}$-caryophyllene, 3-cyclohexen- 1-ol, and ${\gamma}$-curcumene. We evaluated the safety of C. indicum flower oil by conducting acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation tests. Mortality, clinical signs and gross findings of mice were measured for 15 days after the oral single gavage administration of C. indicum flower oil. There were no mortality and clinical signs of toxicity at 2,000 mg/kg body weight/day of C. indicum flower oil throughout the 15 day period. Micronucleated erythrocyte cell counts for all treated groups were not significantly different between test and control groups. Levels of 15.63~500 ${\mu}g$ C. indicum flower oil/plate did not induce mutagenicity in S. Typhimurium and E. coli, with or without the introduction of a metabolic activation system. These results indicate that ingesting C. indicum flower oil produces no acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation.

Analysis of Fish Expression Vectors for Construction of Two MARs Expression Vector System in Fish Cell Line

  • Lim, Hak-Seob;Park, Jin-Young;Hwnag, Jee-Hwang;Kim, Moo-Sang;Lee, Hyung-Ho
    • Journal of Aquaculture
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    • v.13 no.1
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    • pp.29-37
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    • 2000
  • In previously study we isolated several fish matrix attachment regions (MARs) capable of replicating the plasmid by itself. In this study we construct a fish expression vector pBaEGFP(+) containing mud loach ${\beta}$-actin promoter EGFP as reporter gene and SV40 signal. To analyze the effects of the fish expression vector respectively. The fish ARS containing constructs pBaEGFP(+)-ARSs were transfected cells with pBaEGFP(+)-ARS101 and pBaEGFP(+)-ARS223 reduced 10 days to 25 days and then was constant to 30 days after transfection while that of the control vector without ARS element was basal level. The intensity of both constructs showed about 30fold of the intensity compared with the control vector on 30days after transfection individually .E. coli back-transformation analysis shows that pBaEGFP(+)-ARS223 and pBaEGFP(+)-ARS905 maintain in episomal state at least 30 days after transfection. The result indicates that both may be able to replicate the vector in BF-2 cell. Therefore the matrix-attached ARSs enhancing expression of the reporter gene might be useful as a component o the expression vector for transgenic studies.

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Interaction between the third intercellular loop of human $5-HT_6$ serotonin receptor and G protein alpha subunit

  • Park, Yun-Hui;Lee, Won-Kyu;Yu, Yeon-Gyu
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.59-59
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    • 2003
  • Serotonin (5-HT; 5-hydroxytryptamine) exerts multiple effects on central nervous system as well as behaviors such as mood and appetite. The signaling of serotonin is mediated by 7 families of serotonin receptors, designated 5-HT$_1$ to 5-HT$_{7}$. Six families of this receptor are G-protein coupled 7TM receptors, and the third intracellular loop of these receptors is proposed to interact with specific types of G-proteins. To investigate the specific interaction between the third intracellular loop of 5-HT$_{6}$ with G$\square$s, we have constructed a chimera protein that represent the third intracellular loop of 5-HT$_{6}$ within a leucine zipper motifs, In addition an alpha subunit of human G-protein that interact with 5-HT$_{6}$ was cloned into a bacterial expression vector. The two proteins were expressed in E. coli and purified in homogeneity. The interaction of the prepared proteins was examined by ELISA assay. The affinity between the two proteins and effect of insertion mutations were discussed.ussed.d.

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Development of Refolding Process to Obtain Active Recombinant Human Bone Morphogenetic Protein-2 and its Osteogenic Efficacy on Oral Stem Cells

  • Lee, Ji-Hye;Jang, Young-Joo
    • International Journal of Oral Biology
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    • v.42 no.2
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    • pp.71-78
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    • 2017
  • BMP-2 is a well-known TGF-beta related growth factor, having a significant role in bone and cartilage formation. It has been employed to promote bone formation in some clinical trials, and to differentiate mesenchymal stem cells into osteoblasts. However, it is difficult to obtain this protein in its soluble and active form. hBMP-2 is expressed as an inclusion body in the bacterial system. To continuously supply hBMP-2 for research, we optimized the refolding of recombinant hBMP-2 expressed in E. coli, and established an efficient method by using detergent and alkali. Using a heparin column, the recombinant hBMP-2 was purified with the correct refolding. Although combinatorial refolding remarkably enhanced the solubility of the inclusion body, a higher yield of active dimer form of hBMP-2 was obtained from one-step refolding with detergent. The refolded recombinant hBMP-2 induced alkaline phosphatase activity in mouse myoblasts, at $ED_{50}$ of 300-480ng/ml. Furthermore, the expressions of osteogenic markers were upregulated in hPDLSCs and hDPSCs. Therefore, using the process described in this study, the refolded hBMP-2 might be cost-effectively useful for various differentiation experiments in a laboratory.

Recombinant Expression, Isotope Labeling, and Purification of Cold shock Protein from Colwellia psychrerythraea for NMR Study

  • Moon, Chang-Hun;Jeong, Ki-Woong;Kim, Hak-Jun;Heo, Yong-Seok;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2647-2650
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    • 2009
  • Cold shock proteins (Csps) are a subgroup of the cold-induced proteins on reduction of the growth temperature below the physiological temperature. They preferentially bind to single-stranded nucleic acids to translational regulation via RNA chaperoning. Csp plays important role in cold adaptations for the psychrophilic microorganism. Recently, Cold shock protein from psychrophilic bacteria, Colwellia psychrerythraea (CpCsp) has been identified. Three dimensional structures of a number of Csps from various microorganisms have been solved by NMR spectroscopy or X-ray crystallography, but structures of psychrophilic Csps were not studied yet. Therefore, cloning and purification protocols for further structural study of psychrophilic Csp have been optimized in this study. CpCsp was expressed in E. coli with pET-11a vector system and purified by ion exchange, size exclusion, and reverse phase chromatography. Expression and purification of CpCsp in M9 minimal media was carried out and $^{15}N$-labeled proteins with high purity over 90% was obtained. Further study will be carried out to investigate the tertiary structure and dynamics of CpCsp.

Comparison of 2-D RP-RP MS/MS with 1-D RP MS/MS for Proteomic Analysis (단백체 분석을 위한 일차원 및 이차원 역상크로마토그래피의 비교)

  • Moon, Pyong-Gon;Cho, Young-Eun;Baek, Moon-Chang
    • YAKHAK HOEJI
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    • v.54 no.5
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    • pp.377-386
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    • 2010
  • Single-dimensional (1-D) and two-dimensional (2-D) LC methods were utilized to separate peptides from various sources followed by MS/MS analysis. Two-dimensional ultra-high performance liquid chromatography is a useful tool for proteome analysis, providing a greater peak capacity than 1-D LC. The most popular 2-D LC approach used today for proteomic research combines strong cation exchange and reversed-phase LC. We have evaluated an alternative mode for 2-D LC of peptides using 2-D RP-RP nano UPLC Q-TOF Mass Spectrometry, employing reversed-phase columns in both separation dimensions. As control experiments, we identified 129 proteins in 1-D LC and 322 proteins in 2-D LC from E. coli extract peptides. Furthermore, we applied this method to rat primary hepatocyte and a total of 170 proteins were identified from 1-D LC, and 527 proteins were identified from all 2-D LC system. The in-depth protein profiling established by this 2-D LC MS/MS from rat primary hepatocyte could be a very useful reference for future applications in regards to drug induced liver toxicity.

CheY-OmpR Hybrid Protein Acting on the Osmoregulatory System (CheY-OmpR 혼성 단백질의 삼투조절효과)

  • 고민수;박찬규
    • Korean Journal of Microbiology
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    • v.33 no.2
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    • pp.118-124
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    • 1997
  • In the previous study(6), we constructed the CheY-OmpR hybrid, Chp, which affects the expressions of ompF and om pC genes. Here we further characterize these effects and present the regulatory mechanism based on in vivo and in vitro data. Although Chp retained the sequence-specific DNA-binding ability, it was not possible to enhance transcriptional activity, suggesting that it may act as a competitive inhibitor to OmpR. The DNA-binding affinity of Chp was not modulated by phosphorylation of its Che Y portion. Chp was able to increase ompR transcription. FurthemlOre, it was found that the wild-type OmpR also exerts the same effect, which is also eOlltrolled by changes in medium osmolarity and in EnvZ activity.

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Molecular Cloning of Bacteriocin Gene and Biological Control of Plant Pathogen (Bacteriocin 생산 유전자의 Cloning 및 식물병원균에 대한 생물학적 억제)

  • 김교창;육창수;도대홍
    • Microbiology and Biotechnology Letters
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    • v.18 no.1
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    • pp.98-102
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    • 1990
  • A strain of Erwinia spp. was selected from the soil for the production of bacteriocin to the root rot plant pathogen. Bacteriocin producing gene was not located on plasmid but on chromosome. Genomic library of Erwinia spp. were made by using pLAFR 3 as a vector system for cloning of the gene. It was been cloned and expressed in E. coli DH 5 . Bacteriocin producing colony was composed of pLAFR 3 vector and 3.0 kb EcoRI fragment of Erwinia spp. ehromosomal DNA. The inserted fragment (3.0 kb) was possessed a EcoRI and BarnHI restriction sites.

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Galleria mellonella 6-Tox Gene, Putative Immune Related Molecule in Lepidoptera

  • Lee, Joon-Ha;Park, Seung-Mi;Chae, Kwon-Seok;Lee, In-Hee
    • International Journal of Industrial Entomology and Biomaterials
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    • v.21 no.1
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    • pp.127-132
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    • 2010
  • We have characterized full-length cDNA encoding Gall-6-tox protein, which was cloned from the fat body of the immunized Galleria mellonella larvae. The cloned cDNA of Gall-6-tox consists of 1301 nucleotides and contained an open reading frame of 891 nucleotides corresponding to a protein of 296 residues that includes a putative 16-residue signal sequence and a 280-residue mature peptide with a calculated mass of 30,707.73 Da. The deduced mature peptide contains conserved tandem repeats of six cysteine-stabilized alpha beta ($Cs{\alpha}{\beta}$) motifs, which was detected in scorpion toxins and insect defensins. In the sequence homology search, mature Gall-6-tox showed 34% and 28% amino acid sequence homology with Bomb-6-tox from Bombyx mori and Spod-11-tox from Spodoptera frugiperda, respectively. Gall-6-tox orthologs were only found in Lepidopteran species, indicating that this new immune-related gene family is specific to this insect order. RT-PCR analysis revealed that Gall-6-tox was expressed primarily in the larval fat bodies, hemocytes, and midgut against invading bacteria into hemocoel. Moreover, the expression time course of Gall-6-tox was examined up to 24 h in the fat bodies and midgut after injection of E. coli. Altogether, these results suggest that Gall-6-tox is derived from defensins and Gall-6-tox may play a critical role in Lepidoptera immune system.