• Title/Summary/Keyword: E. coli expression

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Heterologous Expression and Characterization of Glycogen Branching Enzyme from Synechocystis sp. PCC6803

  • Lee, Byung-Hoo;Yoo, Young-Hee;Ryu, Je-Hoon;Kim, Tae-Jip;Yoo, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.18 no.8
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    • pp.1386-1392
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    • 2008
  • A gene (sll0158) putatively encoding a glycogen branching enzyme (GBE, E.C. 2.4.1.18) was cloned from Synechocystis sp. PCC6803, and the recombinant protein expressed and characterized. The PCR-amplified putative GBE gene was ligated into a pET-21a plasmid vector harboring a T7 promoter, and the recombinant DNA transformed into a host cell, E. coli BL21(DE3). The IPTG-induced enzymes were then extracted and purified using Ni-NTA affinity chromatography. The putative GBE gene was found to be composed of 2,310 nucleotides and encoded 770 amino acids, corresponding to approx. 90.7 kDa, as confirmed by SDS-PAGE and MALDI-TOF-MS analyses. The optimal conditions for GBE activity were investigated by measuring the absorbance change in iodine affinity, and shown to be pH 8.0 and $30^{\circ}C$ in a 50 mM glycine-NaOH buffer. The action pattern of the GBE on amylose, an $\alpha$-(1,4)-linked linear glucan, was analyzed using high-performance anion-exchange chromatography (HPAEC) after isoamylolysis. As a result, the GBE displayed $\alpha$-glucosyl transferring activity by cleaving the $\alpha$-(1,4)-linkages and transferring the cleaved maltoglycosyl moiety to form new $\alpha$-(1,6)-branch linkages. A time-course study of the GBE reaction was carried out with biosynthetic amylose (BSAM; $M_p{\cong}$8,000), and the changes in the branch-chain length distribution were evaluated. When increasing the reaction time up to 48 h, the weight- and number-average DP ($DP_w$ and $DP_n$) decreased from 19.6 to 8.7 and from 17.6 to 7.8, respectively. The molecular size ($M_p$, peak $M_w{\cong}2.45-2.75{\times}10^5$) of the GBE-reacted product from BSAM reached the size of amylose (AM) in botanical starch, yet the product was highly soluble and stable in water, unlike AM molecules. Thus, GBE-generated products can provide new food and non-food applications, owing to their unique physical properties.

Immune stimulating effects of Astragalus membranaceus and Zanthoxylum schinifolium 1:1 mixture in Raw264.7 cells (Raw264.7 세포에서 황기와 산초 1:1 혼합물의 면역 증진 효과)

  • Il Je Cho;Yeong Eun Yu;Sang Min Lee;Eun Ok Kim;Joon Heum Park;Sea Kwang Ku
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.519-526
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    • 2023
  • Present study explored immunostimulatory effects of Astragalus membranaceus and Zanthoxylum schinifolium 1:1 (w:w) mixture (AZM-1:1) in Raw264.7 cells, mouse macrophage derived cells. Treatment with 100-400 ㎍/mL of AZM-1:1 in Raw264.7 cells significantly increased nitric oxide production in parallel with inducible nitric oxide synthase mRNA expression without affecting cytotoxicity. In addition, AZM-1:1 dose-dependently increased prostaglandin E2 production in conditioned medium along with cyclooxygenase-2 mRNA induction. Moreover, AZM-1:1 induces the transcription of tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1. Immunoblot analyses revealed that AZM-1:1 significantly increased the phosphorylation of mitogen-activated protein kinases, provoked phosphorylation-mediated degradation of inhibitory-κBα, and phosphorylated p65. Furthermore, treatment with AZM-1:1 promoted phagocytosis of Escherichia coli particle labeled with green fluorescence. Taken together, AZM-1:1 may be a promising nutraceutical for stimulation the innate immune system, including macrophages.

Isolation and characterization of sigH from Corynebacterium glutamicum (Corynebacterium glutamicum의 sigH 유전자의 분리 및 기능분석)

  • Kim Tae-Hyun;Kim Hyung-Joon;Park Joon-Sung;Kim Younhee;Lee Heung-Shick
    • Korean Journal of Microbiology
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    • v.41 no.2
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    • pp.99-104
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    • 2005
  • Corynebacterial clones which exert regulatory effects on the expression of the glyoxylate bypass genes were isolated using a reporter plasmid carrying the enteric lacZ fused to the aceB promoter of Corynebacterium glutamicum. Some clones carried common fragments as turned out by DNA mapping technique. Subcloning analysis followed by the measurement of $\beta-galactosidase$ activity in Escherichia coli identified the region responsible for the aceB-repressing activity. Sequence analysis of the DNA fragment identified two independent ORFs of ORF1 and ORF2. Among them, ORF2 was turned out to be responsible for the aceB-repressing activity. ORF1 encoded a 23,216 Da protein composed of 206 amino acids. Sequence similarity search indicated that the ORF may encode a ECF-type $\sigma$ factor and designated sigH. To identify the function of sigH, C. glutamicum sigH mutant was constructed by gene disruption technique and the sigH mutant showed growth retardation as compared to the wild type strain. In addition, the mutant strain showed sensitivity to oxidative-stress generating agent plumbagin. This result imply that sigH is probably involved in the stress response occurring during normal cell growth.

The Effects of Moxifloxacin in Endotoxin-induced Acute Lung Injury (내독소로 유도된 급성폐손상에서 Moxifloxacin의 효과)

  • Baek, Jong Hyun;Lee, Jang Hoon;Lee, Jung Cheul;Lee, Dong Hyup;Moon, Yong Suk;Lee, Young Man
    • Journal of Chest Surgery
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    • v.42 no.1
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    • pp.1-8
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    • 2009
  • Background: The pathophysiology of acute respiratory distress syndrome with sepsis is acute lung injury (ALI) that's' caused by endotoxin (LPS). We evaluate effects of moxifloxacin on LPS-induced ALI in a rat model. Material and Method: The rats were divided into 3 groups as the control group (C), the LPS insult group (L), and the LPS+moxifloxacin treated group (L-M). ALI was induced by endotracheal instillation of E.coli LPS, then moxifloxacin was given in 30 minutes. Five hours later, we checked the lung weight/body weight ratio(the L/BW ratio), the protein & neutrophils in the bronchoalveolar lavage fluid (BALF), the myeloperoxidase (MPO) activity & the malondialdehyde (MDA) content, the expressions of cytosolic and secretory phospholipase $A_2$ (c, $sPLA_2$), and the morphology of the lung with using a light microscope. Result: The L/BW ratio, the protein content and the neutrophil count in the BALF, and the MPO activity and the MDA content in lung were significantly increased in group L compared to group C, and these factors were markedly decreased in group L-M compare to group L. The $cPLA_2$ expression and the $sPLA_2$ expression were increased in group L and the $cPLA_2$ expression was decreased in group L-M. Yet the $sPLA_2$ expression was not changed in group L-M. Morphologically, many inflammatory findings were observed in group L, but not in group L-M. Conclusion: Many of the inflammatory changes of ALI that were caused by LPS insult were ameliorated by moxifloxacin treatment.

Carbon Monoxide Inhibits PMA-induced Differentiation in Human Monocytic THP-1 Cells (단핵구세포주 THP-1의 대식세포로의 분화 및 활성화에서 CO의 억제 효과)

  • Kim, Da Sol;Lee, Mi Sun;Kim, Han Sol;Lee, Hye Yun;Kim, Oh Yun;Kang, Ye Rin;Sohn, Dong Hyun;Kim, Koanhoi;Park, Young Chul
    • Journal of Life Science
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    • v.27 no.2
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    • pp.217-224
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    • 2017
  • Carbon monoxide (CO), a reaction product of cytoprotective enzyme heme oxygenase-1 (HO-1), is a gaseous messenger with anti-proliferative, anti-apoptotic, and anti-inflammatory actions in many cell types. Here, we investigated the role of CO on the process of monocyte differentiation induced by phorbol 12-myristate 13-acetate (PMA) in human monocytic THP-1 cells. CORM-2 (tricarbonyldichlororuthenium (II) dimer, $Ru2Cl_4(CO)_6$), a CO-releasing compound, decreased a marked cell adherence with a slight reduction of proliferation in monocytic THP-1 cells treated with PMA. And, CORM-2 significantly inhibited expression of differentiation markers such as CD14, CD11b plus CD18 (macrophage-1 antigen, Mac-1 or complement receptor 3, CR3) and phagocytosis of carboxylate-modified red fluorescent latex beads, in PMA-stimulated THP-1 cells. For the further experiments, differentiation of PMA-treated cells was enhanced after the initial 2 days stimulus by removing the PMA-containing media then incubating the cells in fresh media for a another 4 days. And, we observed the secretion of inflammatory cytokines and phagocytosis in differentiated macrophages. Treatment with CORM-2 significantly abolished the secretion of IL-6, $TNF-{\alpha}$ and phagocytosis using fluorescence-conjugated E. coli (K-12 strain) bioparticles in lipopolysaccharide (LPS)-stimulated differentiated macrophages. In conclusion, these results suggest that CO inhibits the differentiation of monocytic THP-1 cells as well as the activation of differentiated macrophages.

Effect of antioxidation and antibacterial activity on crude extract and Characterization of American Cockroaches (Periplaneta americana L.) in Korea (국내 서식 미국바퀴(Periplaneta americana L.)의 특성 및 추출물의 항산화·항균 효과)

  • Kim, Jung-Eun;Kim, Seon-Gon;Kang, Sung-Ju;Kim, Chun-Sung;Choi, Yong-Soo
    • Journal of Sericultural and Entomological Science
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    • v.53 no.2
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    • pp.135-142
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    • 2015
  • The American cockroaches, Periplaneta americana L. was the most important worldwide pest species. It has been an public health problems. We were determinated life cycle and extraction of crude extracts by chemical reagents from cockraches (P. americana L.). The extracted crude solution has been antibacterial activity to gram negative bacteria (Pseudomonas aeruginosa, $6.44{\pm}1.03mm$), gram positive bacteria (Bacillus subtilis, $1.88{\pm}0.40mm$), and fungus (Candida albicans, $5.61{\pm}0.57mm$) using radial diffusion assay. We were analysed of up-regulation of Glutathione-S-transferases (GSTs) stimulation, indicating that antioxidantial protein from various classes are simultaneously expressed in a single insect upon infection or injury. The gene from Periplaneta americana L. were cloned, analysed sequence, and measured protein expression by Real Time PCR (Polymerase Chain Reaction).

Effect of Recombinant CagL Immunization on the Gastric Diseases Induced by Helicobacter pylori in Mongolian gerbils (CagL 재조합 단백질 접종후에 Mongolian gerbil에서 나타나는 Helicobacter pylori 감염에 대한 반응)

  • Bak, Eun-Jung;Jang, Sung-Il;Choi, Yun-Hui;Kim, Jin-Moon;Kim, Ae-Ryun;Kim, Ji-Hye;Woo, Gye-Hyeong;Yoo, Yun-Jung;Lee, Sung-Haeng;Cha, Jeong-Heon
    • Korean Journal of Microbiology
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    • v.48 no.2
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    • pp.109-115
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    • 2012
  • Helicobacter pylori is an important factor of chronic gastritis, digestive ulcer, and stomach cancer. CagL, a virulence factor of H. pylori, is well-known as a pilus protein which acts as adhesion to host cell and a component of Type 4 secretion system. In this study, we evaluated the protective response of recombinant CagL protein (rCagL) using Mongolian gerbil animal model for H. pylori infection. The cagL gene was cloned from 26695 H. pylori followed by over-expression and purification of the protein in E. coli. Mongolian gerbils were immunized with rCagL protein mixed with aluminum adjuvant via intramuscular injections once a week during 4 weeks. At a week after the last immunization, the Mongolian gerbils were administrated with H. pylori 7.13 strain into the stomach and sacrificed to measure antibody titer on rCagL by ELISA and bacterial colonization in the stomach, and to examine the histopathological changes and cytokine expression at 6 week after challenge. Antibody titers on recombinant protein were significantly increased from a week after the first immunization. There was no significant change of the number of bacterial colony between control group and immunized group. The relative stomach weight was significantly decreased in immunized group, but the significant change of histopathological assessment was not observed in the stomach. Cytokine expression such as IL-$1{\beta}$ and KC also was not significantly different between control and immunized groups. These results indicate that rCagL could effectively induce the formation of the specific IgG antibodies. However, bacterial colonization and histopathological lesions could not be inhibited by the immunization in the stomach, indicating not enough protection against H. pylori infection. We consider that along with CagL other adequate antigens could be needed stimulating immune response and inducing protective effects against gastric disease, and also a better adjuvant could be considered.

Recombination and Expression of VP1 Gene of Infectious Pancreatic Necrosis Virus DRT Strain in a Baculovirus, Hyphantria cunea Nuclear Polyhedrosis Virus (전염성 췌장괴저바이러스 DRT Strain VP1유전자의 Baculovirus Hyphantria cunea Nuclear Polyhedrosis Virus에 재조합과 발현)

  • Lee, Hyung-Hoan;Chang, Jae-Hyeok;Chung, Hye-Kyung;Cha, Sung-Chul
    • The Journal of Korean Society of Virology
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    • v.27 no.2
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    • pp.239-255
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    • 1997
  • Expression of the cDNA of the VP1 gene on the genome RNA B segment of infectious pancreatic necrosis virus (IPNV) DRT strain in E. coli and a recombinant baculovirus were carried out. The VP1 gene in the pMal-pol clone (Lee et al. 1995) was cleaved with XbaI and transferred into baculovirus transfer vector, pBacPAK9 and it was named pBacVP1 clone. The VP1 gene in the pBacVP1 clone was double-digested with SacI and PstI and then inserted just behind T5 phage promoter and the $6{\times}His$ region of the pQE-3D expression vector, and it was called pQEVPl. Again, the $6{\times}$His-tagged VP1 DNA fragment in the pQEVP1 was cleaved with EcoRI and transferred into the VP1 site of the pBacVP1, resulting pBacHis-VP1 recombinant. The pBacHis-VP1 DNA was cotransfected with LacZ-Hyphantria cunea nuclear polyhedrosis virus (LacZ-HcNPV) DNA digested with Bsu361 onto S. frugiperda cells to make a recombinant virus. One VP1-gene inserted recombinant virus was selected by plaque assay. The recombinant virus was named VP1-HcNPV-1. The $6{\times}$His-tagged VP1 protein produced by the pQEVP1 was purified with Ni-NTA resin chromatography and analyzed by SDS-PAGE and Western blot analysis. The molecular weight of the VP1 protein was 94 kDa. The recombinant virus, VP1-HcNPV-1 did not form polyhedral inclusion bodies and expressed VP1 protein with 95 kDa in the infected S. frugiperda cells, which was detected by Western blot. The titer of the VP1-HcNPV-1 in the first infected cells was $2.0{\times}10^5\;pfu/ml$ at 7 days postinfection.

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Overexpression and Periplasmic Transport of 5-Enolpyruvylshikimate 3-Phosphate Synthase in E. coli (대장균에서 5-Enolpyruvylshikimate 3-Phosphate Synthase의 대량 발현 및 Periplasmic Space로의 Transport)

  • 김남일;임재윤;조태주
    • Korean Journal of Microbiology
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    • v.33 no.1
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    • pp.1-6
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    • 1997
  • 5-Enolpyruvylshikimate 3-phosphate(EPSP) synthase is the sixth enzyme of the shikimate pathway that synthesizes aromatic amino acids. The enzyme is a primary target for the glyphos'lte which is a broad-spectrum and environmetally safe herbicide. As a first step toward development of glyphpsate-resistant EPSP synthase, the EPSP synthase gene(aroA) was amplified by polymerase chain reaction and cluned into pET-25b vector. In this construct. designated pET-aro, the aroA gene is expressed under control of strong T7 promoter. and the EPSP synthase is produced as a fusion protein with pelB leader at N-terminus and HSV-tag and His-tag at C-terminus. When the pET-aro clone was induced to produce the enzyme, it was found that the EPSP synthase was successfully exported to peri plasmic space. The periplasmic transport was greatly dependent on the induction temperatures. Among the induction temperatures examined($25^{\circ}C$, $30^{\circ}C$, $34^{\circ}C$ and $37^{\circ}C$). induction at $34^{\circ}C$ gave rise to maximal periplasmic transport. The recomhinant EPSP synthase could have been purified hy $Ni^{2+}$ -affinity chromatography using the His-tag. and detected hy anti-HSV -tag antibody. The recombinant EPSP synthase also hound to phosphocellulose resin and was eluted hy shikimate 3-phosphate and phosphoenolpyruvate. as expected. The recombinant EPSP synthase purified from phosphocellulose resin showed typical EPSP synthase activity.

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Molecular Cloning and Expression of a Gene for Outer Membrane Protein H in Pasteurella multocida (A:3) : Production of Antisera against the OmpH (파스튜렐라 (A:3)외막 단백질 H의 유전자 클론닝$\cdot$발현 및 면역혈청 생산)

  • Kim Younghwan;Hwang Heon;Lee Sukchan;Park Eun-Seok;Yoo Sun-Dong;Lee Jeongmin;Yang Joo-Sung;Kwon MooSik
    • Microbiology and Biotechnology Letters
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    • v.33 no.4
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    • pp.274-280
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    • 2005
  • Pasteurella multocida is known to cause widespread infections in husbandry. To induce homologous and heterologous immunity against the infections, outer membrane proteins (OMPs) in the envelope of P. multocida are thought to be attractive vaccine candidates. Outer membrane protein H is considered as the major component of OMPs. In this study, a gene for OmpH was isolated from pathogenic P. multocida serogroup A. The gene was composed of 1,047 nucleotides coding 348 amino acids with signal peptide of 20 amino acids. The amino acid composition showed about 80 to 98 per cent sequence homologies among other 10 strains of P. multocida serogroup A, reported so far. A recombinant ompH, from which signal peptide was truncated, was generated using pRSET A to name 'pRSET A/OmpH-F2'. The pRSET A/OmpH-F2 was well expressed in E. coli BL21(DE3). The truncated OmpH was purified using nickel-nitrilotriacetic acid (Ni-NTA) affinity column chromatography. Its molecular weight was registered to be 40 kDa on SDS-PAGE gel. In order to generate immunesera against the OmpH, 50 ug of the protein was intraperitoneally injected into mice three times. The anti-OmpH immuneserum recognized about $5{\times}10^{-2}$ng quantity of the purified OmpH. It can be used for an effective vaccine production to prevent fowl cholera caused by pathogenic P. multocida (Serogroup A).