• BMB Reports
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• 제28권3호
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• pp.216-220
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• 1995

cDNA for human cholesteryl ester transfer protein (CETP), a potent atherogenic plasma protein that redistributes the neutral lipids among lipoproteins, was expressed in recombinant vaccinia virus-infected cells (CV-1). Two insertion vectors regulated by different promoters were constructed. The vectors were introduced into human thymidine kinase-negative ($TK^-$) 1438 cells infected with wild-type vaccinia virus (WR strain). Recombinant viruses were selected with 5-bromodeoxyuridine (BUdR) and X-gal and identified with DNA dot blot analysis (vSC11-CETP and vTM1-CETP). The CETP cDNA insert in the recombinant vaccinia virus genome was identified by Southern blot analysis. Transcription of CETP cDNA in CV-1 cells infected with recombinant vaccinia virus was monitored by Northern blot analysis using the CETP cDNA as a probe. Positive signals were detected at 1.8 kb in cells infected with vSC11-CETP and at 2.3 kb in cells infected with vTM1-CETP. The recombinant vaccinia virus-infected CV-1 cells were shown to produce functional CETP when the culture medium was subjected to the CETP assay.

• Korean Chemical Engineering Research
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• 제47권5호
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• pp.624-629
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• 2009

분자진화방법을 이용하여 불용성 단백질을 가용성 단백질로 개량하고자 할 때 가장 중요한 과정은 발현 단백질의 세포 내 폴딩 및 용해도를 어떻게 측정하고 선별할 수 있는가에 있다. 본 연구에서는 ampicillin에 저항성을 가지는 beta-lactamase를 목적 단백질과 접합 형태로 발현하여 목적 단백질의 용해도를 측정 및 선별할 수 있는 방법을 구축하였다. 이를 위하여 먼저 beta-lactamase C-말단에 목적 단백질을 링커를 이용하여 접합단백질 형태로 발현시킬 수 있는 발현 시스템을 구축하였고, 구축된 발현시스템이 대장균의 ampicillin의 저항성을 향상시킴을 확인하였다. 구축된 발현시스템에 용해도가 비교적 높은 adenine deaminase와 aspartate aminotranseferase, 용해도가 매우 낮은 GlcNAc-2-epimerase 세가지 단백질의 유전자를 클로닝하여 Ampicillin 농도에 따라 목적 단백질의 용해도가 세포 성장에 미치는 영향을 조사하였다. Ampicillin 농도 $200{\mu}g/mL$에서 가용성 단백질인 adenine deaminase와 aspartate aminotranseferase의 접합 단백질 발현은 세포 성장을 보이는 반면, 불용성 단백질인 GlcNAc-2-epimerase 접합 단백질 발현은 세포 성장을 저해함을 확인하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.186-189
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• 2003

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a potent immunogen as well as major virulence factor. In order to express the recombinant urease in tobacco plants, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a plant expression vector. The recombinant vector was transformed to tobacco plants. The integration of the recombinant plasmids into tobacco chromosomal genome was verified by genomic PCR. Expression to mRNA was confirmed by Northern blot analysis, and expression to recombinant urease protein was observed by Western blot analysis. These results showed that the recombinant urease can be produced in tobacco plants and will be tested for immune response to use as an edible vaccine.

• 한국어병학회지
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• 제22권2호
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• pp.147-153
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• 2009

To study the biological activity of interleukin-$1\beta$(IL-$1\beta$), a proinflammatory cytokine, in nile tilapia, Oreochromis niliticus, the recombinant tilapia IL-$1\beta$ was produced in E. coli cells based on pQE vector. Ni-NTA (nitriloacetic acid) metal affinity chromatography was used to purify recombinant protein. The eluted fractions exhibited a single band of protein with a molecular weight of about 25kDa, which is in close agreement with 25.4 kDa predicted by the cDNA sequence. The biological activity of the purified recombinant tilapia IL-$1\beta$ was tested through its effects on IL-$1\beta$ gene expression, which are known as IL-$1\beta$ inducible genes in mammals and fishes. IL-$1\beta$ gene expression induced by poly I:C, a synthetic double stranded RNA, was also assessed in tilapia head kidney cells. IL-$1\beta$ gene expression was analysed using QPCR (quantitative polymerase chain reaction). The ratio of the indicated gene expression was expressed as the relative mRNA level to $\beta$-actin mRNA level, which is constitutively expressed in macrophages. Consequently, head kidney cells incubated for three hours with rIL-$1\beta$(10, 2, 1 $\mu{g}$/ml) showed a dose dependent increase in IL-$1\beta$ mRNA levels and 1 $\mu{g}$/ml of poly I:C was also able to induce IL-$1\beta$ gene expression in head kidney in tilapia.

• International Journal of Industrial Entomology and Biomaterials
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• 제30권2호
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• pp.50-57
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• 2015

Porcine circovirus type 2 (PCV2) is an important infectious swine virus causing postweaning multisystemic wasting syndrome (PMWS). PCV2 capsid protein, encoded by ORF2 has type-specific epitopes, is very immunogenic, and is associated with the induction of neutralizing antibodies. For the efficient production of capsid protein, recombinant Autographa californica nucleopolyhedroviruses were generated to express ORF2 fused with two forms of a partial polyhedrin. Recombinant capsid protein was produced successfully with the partial polyhedrin fusion form and the yield was high, as was shown by SDS-PAGE. Production of recombinant capsid proteins in insect cells was confirmed by Western blot analysis using anti-His monoclonal antibody, anti-ORF2 monoclonal antibody, and anti-PCV2 porcine serum. Fusion expression with amino acids 19 to 110 of the polyhedrin increased the production of recombinant capsid protein, but fusion with amino acids 32 to 85 did not. Additionally, PCV2 capsid protein is a glycoprotein; however, the glycosylation of recombinant protein was not observed. The results of an Enzyme-linked immunosorbent assay (ELISA) showed that recombinant capsid proteins could be utilized as antigens for fast, large-scale diagnosis of PCV2-infected pigs. Our results suggest that the fusion expression of partial polyhedrin is able to increase the production of recombinant PCV2 capsid protein in insect cells.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권2호
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• pp.49-53
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• 2016

Bone morphogenetic proteins (BMPs) are essential growth factors for bone formation, skeletal development and bone regeneration. The BMP-2/7 heterodimer is known to have remarkable effects on osteogenic induction that are even stronger than the BMP-2 or BMP-7 homodimers. We designed a recombinant human BMP-2/7 (rhBMP-2/7) heterodimer protein with four glycine residues between BMP-2 and BMP-7 protein to facilitate free bond rotation of domains. The Baculovirus Expression Vector System (BEVS) is routinely used to produce recombinant proteins in the milligram scale. In this study, the BEVS was used to express the rhBMP-2/7 protein whrer the recombinant baculovirus was recovered in the host Sf9 cells. To confirm the biological activity of rhBMP-2/7 protein secreted from the BEVS as an osteogenic differentiation and induction factor, we measured the BMP-induced ALP activity. rhBMP-2/7 could be used as an alternative to BMPs to overcome limitations like short half-life and requirement for high concentrations. Furthermore, rhBMP-2/7 may be an efficient tool for various application studies such as bone regeneration and skeletal development.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1281-1287
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• 2017

Bone morphogenetic protein-4 (BMP-4) is considered to have therapeutic potential for various diseases, including cancers; however, the high expression of biologically active recombinant human BMP-4 (rhBMP-4) needed for its manufacture for therapeutic purposes has yet to be established. In the current study, we established a recombinant Chinese hamster ovary (rCHO) cell line overexpressing rhBMP-4 as well as a production process using 7.5-l bioreactor (5 L working volume). The expression of the mature rhBMP-4 was significantly enhanced by recombinant furin expression. The combination of a chemically defined medium and a nutrient supplement solution for high expression of rhBMP-4 was selected and used for bioreactor cultures. The 11-day fed-batch cultures of the established rhBMP-4-expressing rCHO cells in the 7.5-L bioreactor produced approximately 32 mg/l of rhBMP-4. The mature rhBMP-4 was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure, resulting in a recovery rate of approximately 55% and a protein purity greater than 95%. The N-terminal amino acid sequences and N-linked glycosylation of the purified rhBMP-4 were confirmed by N-terminal sequencing and de-N-glycosylation analysis, respectively. The mature purified rhBMP-4 has been proved to be functionally active, with an effective dose concentration of $EC_{50}$ of 2.93 ng/ml.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.946-948
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• 2013

베큘로바이러스 시스템이 제조되었는데 이것은 polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) 유전자를 재조합한 것이다. 본 재조합벡터 시스템은 인간 섬유아세포에 적용하여 시험하였고 재조합된 유전자의 전이와 유전자 발현을 대조 벡터시스템과 비교하였다. 본 연구로부터 새롭게 제작된 본 베큘로바이러스 시스템이 유전자의 전이와 유전자 발현 면에서 대조 벡터시스템 보다 고효율을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.621-629
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• 2022

Bacterial outer membrane vesicles (OMVs) typically contain multiple immunogenic molecules that include antigenic proteins, making them good candidates for vaccine development. In animal models, vaccination with OMVs has been shown to confer protective immune responses against many bacterial diseases. It is possible to genetically introduce heterologous protein antigens to the bacterial host that can then be produced and relocated to reside within the OMVs by means of the host secretion mechanisms. Accordingly, in this study we sought to develop a novel platform for recombinant OMV (rOMV) production in the widely used bacterial expression host species, Escherichia coli. Three different lipoprotein signal peptides including their Lol signals and tether sequences-from Neisseria meningitidis fHbp, Leptospira interrogans LipL32, and Campylobactor jejuni JlpA-were combined upstream to the GFPmut2 model protein, resulting in three recombinant plasmids. Pilot expression studies showed that the fusion between fHbp and GFPmut2 was the only promising construct; therefore, we used this construct for large-scale expression. After inducing recombinant protein expression, the nanovesicles were harvested from cell-free culture media by ultrafiltration and ultracentrifugation. Transmission electron microscopy demonstrated that the obtained rOMVs were closed, circular single-membrane particles, 20-200 nm in size. Western blotting confirmed the presence of GFPmut2 in the isolated vesicles. Collectively, although this is a non-optimized, proof-of-concept study, it demonstrates the feasibility of this platform in directing target proteins into the vesicles for OMV-based vaccine development.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.128-137
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• 2023

Transcriptome analysis revealed that the sinR gene encoding a transition-state regulator of Bacillus pumilus, genetically close to B. subtilis, was expressed at high levels during growth. The sinR gene is the second gene of the sinIR operon consisting of three promoters and two structural genes in B. subtilis. This study used the sinIR promoter of B. subtilis DB104 to construct a recombinant protein expression system. First, the expression ability depending on the number of sinIR promoter was investigated using enhanced green fluorescent protein (eGFP). The expression level of eGFP was slightly higher when using two promoters (Psin2) than using original promoters. The Psin2 promoter was further engineered by modifying the repressor binding site and -35 and -10 regions. Shine-Dalgarno (SD) sequence of the sinI gene was modified to the consensus sequence. Finally, combining the engineered Psin2 promoter with the modified SD sequence increased the expression level of eGFP by about 13.4-fold over the original promoter. Our results suggest that the optimized sinIR promoter could be used as a novel tool for recombinant protein expression in B. subtilis.