• 대한수의학회지
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• 제61권2호
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• pp.19.1-19.7
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• 2021

Feline panleukopenia virus (FPV) causes leukopenia and severe hemorrhagic diarrhea, killing 50% of naturally infected cats. Although intact FPV can serve as an antigen in the hemagglutination inhibition (HI) test, an accidental laboratory-mediated infection is concern. A non-infectious diagnostic reagent is required for the HI test. Here, we expressed the viral protein 2 (VP2) gene of the FPV strain currently prevalent in South Korea in a baculovirus expression system; VP2 protein was identified by an indirect immunofluorescence assay, electron microscopy (EM), Western blotting (WB), and a hemagglutination assay (HA). EM showed that the recombinant VP2 protein self-assembled to form virus-like particles. WB revealed that the recombinant VP2 was 65 kDa in size. The HA activity of the recombinant VP2 protein was very high at 1:2¹⁵. A total of 143 cat serum samples were tested using FPV (HI-FPV test) and the recombinant VP2 protein (HI-VP2 test) as HI antigens. The sensitivity, specificity, and accuracy of the HI-VP2 test were 99.3%, 88.9%, and 99.3%, respectively, compared to the HI-FPV test. The HI-VP2 and HI-FPV results correlated significantly (r = 0.978). Thus, recombinant VP2 can substitute for intact FPV as the serological diagnostic reagent of the HI test for FPV.

• Journal of Microbiology
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• 제40권1호
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• pp.77-81
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• 2002

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic hematspoietic growth factor involved in the development of myeloid cells from bone marrow, and an activator of mature myeloid cells functioning in a variety of antimicrobial and inflammatory responses. Recently, recombinant GM-CSF is increasingly under clinical study for treatment of various diseases including cancer, infectious diseases and hematopoietic diseases as well as for an immune response modulator, In this study, we constructed a recombinant human GM-CSF (rhGM-CSF) expression plasmid with a pelB leader sequence and His. Tag under T7 promoter control. The expression construct was shown to produce a recombinant protein of 20 kDa in the 8M urea preparation, indicating the rhGM-CSF may be expressed as an insoluble inclusion form. The 20 kDa recombinant protein in 8M urea was transformed into the water-so1ub1e form by dialysis against PBS buffer (phosphate buffered saline). The soluble rhGM-CSF protein was shown to stimulate colony formation and cell proliferation in vitro, indicating that the rhGM-CSF could be refolded into its native form to show colony stimulating activity.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.954-957
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• 2015

polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) 유전자로 구성된 재조합 베큘로바이러스를 제작하였다. 본 재조합 베큘로바이러스 시스템은 여러가지 세포주와 여러 가지 조직에 감염하여 시험하였고 재조합된 유전자의 전달과 유전자 발현을 대조 벡터시스템과 비교하였다. 본 연구의 결과로 제작된 재조합 베큘로바이러스 시스템은 유전자의 전달과 발현에 있어서 대조 벡터시스템 보다 효능과 안전성면에서 우수하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.994-996
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• 2012

본 연구실에서는 새로운 베큘로바이러스 벡터 시스템을 구축하였다. 즉 본 벡터 시스템은 polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), protein transduction domain (PTD)을 코딩하는 유전자들로 구성 되어있다. 이렇게 새로이 제작된 베큘로바이러스 벡터 시스템과 대조군의 벡터 시스템과 효율과 발현율을 비교하였다. 그 결과 본 연구실에서 제작된 베큘로바이러스 벡터 시스템이 다른 대조군의 벡터 시스템에 비해 효과적임을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4337-4340
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• 2011

The vitamin D receptor binding peptide, VDRBP, was overexpressed as a fused form with the ubiquitin molecule in Rosetta(DE3)pLysS, a protein production strain of Escherichia coli harboring an induction controller plasmid. The fusion protein was bound to the immobilized metal ions, and the denaturation and renaturation of the fusion protein were performed as a part of the purification procedure. After the elution of the fusion protein, the peptide hormone was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The purity of the resulting peptide fragment was checked by MALDI-TOF mass and NMR spectroscopy. The final yields of the target peptide were around 5 and 2 mg per liter of LB and minimal media, respectively. The recombinant expression and purification of this peptide will enable structural and functional studies using multidimensional NMR spectroscopy and X-ray crystallography.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1062-1068
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• 2004

Leptin has a major role in the regulation of food intake and energy homeostasis. In addition, leptin participates in many physiological functions including regulation of lipid metabolism. Bovine recombinant leptin protein was produced in E. coli cells in order to understand function of leptin in the regulation of lipid metabolism. The leptin expression vector was constructed in pGEX-4T-3 vector and transformed into E. coli BL21 cells. Expression of the GST-leptin fusion protein was induced with IPTG. The fusion protein was purified using glutathione sepharose 4B batch method, and the recombinant leptin was eluted after thrombin protease digestion. The effect of leptin on glucose transport was examined in the differentiated adipocytes of 3T3-L1 cells. Leptin had no effect on basal and insulin-stimulated glucose transport in 3T3-L1 cells (p>0.05). Effect of recombinant leptin on glucose and acetate transport was examined in adipose tissues of Korean cattle (Hanwoo). Insulin stimulated glucose transport in both intramuscular and subcutaneous adipose tissues (p<0.05), but leptin did not affect glucose transport in both adipose tissues (p>0.05). Insulin stimulated acetate transport in bovine adipose tissues (p<0.05), but leptin did not affect acetate transport (p>0.05). Northern and RT-PCR analyses showed that mRNA levels of uncoupling protein-2 were increased by leptin treatment in 3T3-L1 cells without statistical difference (p>0.05). In conclusion, bovine recombinant leptin did not affect glucose and acetate transport in both 3T3-L1 adipocytes and bovine adipose tissues, while it stimulates UCP-2 mRNA expression in 3T3-L1 cells.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.122-128
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• 1992

Post-translational modifications of the nucleocapsid protein of bovine coronavirus (Quebec strain) were investigated. Coronavirions were radiolabelled in vivo with inorganic $[^{32}P]$orthophosphate and analysed by SDS-PAGE, followed by autoradiography. A single polypeptide with a migration rate of 55 KDa was identified by metabolic phosphate labelling, demonstrating that the nucleocapsid protein of bovine coronavirus was a phosphoprotein. A gene encoding the nucleocapsid protein was inserted immediately downstream from the polyhedrin promoter of Autographa californica nuclear polyhedrosis baculovirus. Spodoptera frugiperda cells infected with this recombinant baculovirus synthesized a 55 KDa polypeptide, as demonstrated by immunoprecipitation with anti-nucleocapsid monoclonal antibody. The recombinant nucleocapsid protein synthesized in Spodoptera cells could also be labelled by $[^{32}P]$orthophosphate. Phosphoamino acid analysis showed that both serine and threonine residues were phosphorylated in authentic, as well as in recombinant nucleocapsid proteins, with a relative phosphorylation ratio of 7:3. Our studies demonstrated that the nucleocapsid protein of bovine coronavirus was a serine and threonine-phosphorylated protein and that Spodoptera insect cells were able to properly phosphorylate the relevant foreign proteins.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1397-1401
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• 2005

Bone morphogenetic protein-4 (BMP-4) is a signaling homodimeric molecule that acts as a morphogen to influence cell fate in a concentration-dependent manner. The limited supply of a pure preparation of BMP-4, due to very low level of their expression in vivo, makes it difficult not only to study the biological activities of BMPs, but also to use them as a clinical tool. For a large-scale production of BMP-4, human BMP-4 cDNA was expressed in Chinese hamster ovary (CHO) cells by a recently development vector system, which confers position-independent stable expression of the foreign genes. The CHO cell line expressing recombinant human BMP-4 (rhBMP-4) at the level of $7\;{\mu}g/ml$ could be obtained after stepwise selection with methotrexate. This level of expression is about 70 times higher than those previously reported. The partially processed form of BMP-4 as well as mature form could be detected, when the aliquots of culture media were analyzed by Western blot. The glycosylation pattern and biological activity of the rhBMP-4 were determined by glycosidase treatment and the induction rate of alkaline phosphatase in mouse osteoblastic cells.

• 대한의생명과학회지
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• 제8권3호
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• pp.107-113
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• 2002

Enterohemorrhagic Escherichia coli (EHEC) strains of serotype O157:H7 have been shown to colonize the intestinal epithelial cell by the attaching and effacing (AE) mechanism. The AE lesion is mediated by an intimin, of which production and expression are controlled by a 3-Kb eaeA gene located EHEC chromosomal DNA. If the eaeA gene is mutated, EHEC O157:H7 strains lose capacity of adhesion to intestinal epithelial cells. In this study, a 891 bp of the 3'-end region of a gamma intimin was amplified by polymerase chain reaction (PCR). The PCR product was inserted into pSTBlue-1 cloning vector and transformed into DE3 (BL21) competent cell. After plasmid mini-preparation and restriction enzyme digestion of eaeA/891-pSTBlue-1 vector, target eaeA gene was re-inserted into pET-28a expression vector and was transformed. Then the expression of recombinant eaeA/891 (891 bp) gene was induced by isopropyl-$\beta$-D-thiogalactopyranoside (IPTG). The expression of the 40-KDa recombinant protein was identified in SDS-PAGE and confirmed by immunoblotting using the His.Tag$^{\circledR}$ and T$_{7}$.Tag$^{\circledR}$ monoclonal antibody. This recombinant protein expressed by eaeA gene could be applied in further studies on the mechanisms of E. coli O157:H7 infection and the development of recombinant vaccine.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.322-328
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• 2013

In this study, we show the expression and purification of the human recombinant farnesoid X receptor (FXR)- ligand binding domain (LBD) protein in E. coli using a double cistronic vector, pACYCDuet-1, as a soluble form. We describe here the expression and characterization of a biologically active $FXR-LBD_{(248-476)}$. When expressed in the influence of bacterial promoters ($P_{T7}$ and $P_{Tac}$) of the single cistronic expression vectors, the human recombinant $FXR-LBD_{(248-476)}$ was found to be totally insoluble. However, by using a double cistronic expression vector, we were able to obtain the human recombinant $FXR-LBD_{(248-476)}$ in a soluble form. To allow for biological activities, we have subcloned into the pACYCDuet-1 vector, expressed in E. coli cells at some optimized conditions, and purified and characterized the human recombinant active $FXR-LBD_{(248-476)}$ proteins using the fluorescence polarization assay. This suggests that the expression of FXR-LBD in a double cistronic vector improves its solubility and probably assists its correct folding for the biologically active form of the proteins. We suggest that this may represent a new approach to high expression of other nuclear receptors and may be useful as well for other classes of heterodimeric protein partners.