• Reproductive and Developmental Biology
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• 제33권2호
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• pp.71-76
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• 2009

Salivary lipocalin (SAL1) is a member of the lipocalin protein family that has a property to associate with many lipophilic molecules. The importance of SAL1 during pregnancy in pigs has been suggested by our previous study which has shown that SAL1 is expressed in the uterine endometrium in a cell type- and implantation stage-specific manner and secreted into the uterine lumen. However, function of SAL1 in the uterus during pregnancy in pigs is not known. To understand SAL1 function in the uterus during pregnancy, we generated recombinant porcine SAL1 protein in an insect cell line. Porcine SAL1 cDNA was cloned into a baculovirus expression vector using RT-PCR and total RNA from uterine endometrium on day 12 of pregnancy, and the expression vector was used to generate recombinant Bacmid containing the SAL1 gene. The recombinant Bacmid was then transfected Sf9 cell to produce recombinant baculovirus. By infecting Sf9 cell with recombinant baculovirus, we established a SAL1-expressing insect cell expression system. Immunoblot analysis confirmed SAL1 expression in the infected cells. Recombinant SAL1 produced by the Sf9 cell line will be useful for understanding physiological function of SAL1 during pregnancy in pigs.

• Molecules and Cells
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• 제28권1호
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• pp.19-24
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• 2009

The goal of this study was to create a novel baculovirus expression system that does not require recombinant virus purification steps. Transfection of insect cells with transfer vectors containing barnase under control of the Cotesia plutellae bracovirus (CpBV) promoters ORF3004 or ORF3005 reduced cell growth. Co-transfection with bApGOZA DNA yielded no recombinant viruses and nonrecombinant backgrounds. To further investigate the detrimental effects of barnase on insect cells, two recombinant bacmids harboring the barnase gene under control of the CpBV promoters, namely bAcFast-3004ProBarnase and bAcFast-3005ProBarnase, were constructed. While no viral replication was observed when only the recombinant bacmids were transfected, recombinant viruses were generated when the bacmids were co-transfected with the transfer vector, pAcUWPolh, through substitution of the barnase gene with the native polyhedrin gene by homologous recombination. Moreover, no non-recombinant backgrounds were detected from unpurified recombinant stocks using PCR analysis. These results indicate that CpBV promoters can be used to improve baculovirus expression vectors by means of lethal gene expression under the control of these promoters.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1583-1590
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• 2006

T4 endonuclease V (T4 endo V) [EC 3. 1. 25. 1], found in bacteriophage T4, is responsible for excision repair of damaged DNA. The enzyme possesses two activities: a cyclobutane pyrimidine dimer DNA glycosylase (CPD glycosylase) and an apyrimidic/apurinic endonuclease (AP lyase). T4 denV (414 bp cDNA) encoding T4 en do V (138 amino acid) was synthesized and expressed using either an expression vector, pTriEx-4, in E. coli or a baculovirus AcNPV vector, pBacPAK8, in insect cells. The recombinant His-Tag/T4 endo V (rHis-Tag/T4 endo V) protein expressed from bacteria was purified using one-step affinity chromatography with a HiTrap Chelating HP column and used to make rabbit anti-His-Tag/T4 endo V polyclonal antibody for detection of recombinant T4 endo V (rT4 endo V) expressed in insect cells. In the meantime, the recombinant baculovirus was obtained by cotransfection of BacPAK6 viral DNA and pBP/T4 endo V in Spodoptera frugiperda (Sf21) insect cells, and used to infect Sf21 cells to overexpress T4 endo V protein. The level of rT4 endo V protein expressed in Sf21 cells was optimized by varying the virus titers and time course of infection. The optimal expression condition was set as follows; infection of the cells at a MOI of 10 and harvest at 96 h post-infection. Under these conditions, we estimated the amount of rT4 endo V produced in the baculovirus expression vector system to be 125 mg/l. The rT4 endo V was purified to homogeneity by a rapid procedure, consisting of ion-exchange, affinity, and reversed phase chromatographies, based on FPLC. The rT4 endo V positively reacted to an antiserum made against rHis-Tag/T4 endo V and showed a residual nicking activity against CPD-containing DNA caused by UV. This is the first report to have T4 endo V expressed in an insect system to exclude the toxic effect of a bacterial expression system, retaining enzymatic activity.

• 한국잠사곤충학회지
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• 제44권2호
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• pp.69-73
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• 2002

본 연구는 누에신 단백질의 대량발현을 통해 농업용 소재로서 이용하고자 하는 연구의 일환으로 누에 핵다각체병 바이러스 유래의 pBm10po1-Xa 벡터에 누에신 유전자를 도입하여 누에 배양세포(Bm5) 및 누에 생체에서 발현한 결과 누에신 전사체는 바이러스 접종 후 1일째부터 발현되기 시작하여 5일째에 최대로 발현되었음을 확인할 수 있었고, 누에신 단백질은 3일째부터 발현량이 증가하여 5일째까지 계속 지속적으로 발현되었으나 그 발현량은 전사체에서 처럼 많지 않음을 확인할 수 있었으며, 누에신 단백질의 발현량은 누에 세포에 비해 누에 생체에서 기대만큼 그 발현량이 많지 않았다. 또한 누에신의 베큘로바이러스 발현계 (baculovirus expression vector system, BEVS)를 이용하여 세포내 및 번역후 변형과정을 통하여 세포외로 분비된 누에신의 발현양상을 확인한 결과 세포내에 비해 세포외로 분비시 그 발현량이 현저히 줄어들었음을 확인할 수 있었다. 따라서 베큘로바이러스 발현계를 이용하여 외래 단백질을 생산할 경우 정확한 메카니즘은 밝혀지지 않았으나 강력한 프로모터에 의해 세포내 단백질 생산량은 많은데 비해 정확한 단백질 고차구조 형성을 도와주는 foldase 및 chaperon의 양은 한정되어져 있으므로 정확한 고차구조를 형성하여 세포외로 분비되는 생물학적 활성을 띠는 단백질은 매우 적은 양간이 발현됨을 확인할 수 있었다. 그러므로 추후 누에 신 단백질 대량생산을 위해서는 분비 프로세싱의 해명 및 번역 후 변형과정의 개선을 통한 발현계의 개량이 시급히 요구된다.

• 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.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.533-536
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• 2019

재조합 배큘로 바이러스는 배양 된 곤충 세포에서 이종 유전자를 발현하는데 널리 사용된다. 재조합 배큘로 바이러스는 광범위한 포유류 세포 유형에서 재조합 단백질의 발현을위한 유전자 전달 벡터로서 작용할 수있다. 바큘로 바이러스 시스템은 안전성, 대규모 및 높은 수준의 유전자 발현 관점에서 중요한 이점을 갖는다. 본 연구에서는 pOPINEneo-3C-GFP 벡터로부터 재구성 된 바큘로 바이러스 벡터를 사이토 메갈로 바이러스 (CMV) 프로모터, 강화 된 녹색 형광 단백질 (EGFP) 및 p53과 NcoI 및 XhoI로 재조합시켰다. 이러한 재조합 벡터를 다양한 세포 및 세포주에 감염시켰다. 이와 같이 개발 된 바큘로 바이러스 벡터는 재조합 유전자의 전이 및 발현을 통상적 인 벡터와 비교하여 분석 하였다. 이러한 결과는 바큘로 바이러스 벡터가 대조군 벡터보다 전이 및 전이에서 더 높은 효율을 갖는다는 것을 시사한다. 본 연구는 과학 기술부, 한국 정보 기술 진흥 기금 (MSIP)이 후원하는 한국 연구 재단(NRF)을 통해 중견 연구원 프로그램 (NRF-2016R1A2B4016552)을 통해 지원되었다.

• 대한바이러스학회지
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• 제28권3호
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• pp.225-232
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• 1998

We have expressed GFP in Sf9 and Bm5 cells or Bombyx mori larvae by using Ac-Bm hybrid virus capable of replicating in both Bm5 and Sf9 cells. Genomic DNA of Ac-Bm hybrid virus expressing ${\beta}$-galactosidase was cotransfected with baculovirus transfer vector containing GFP gene, pBacPAK-GFP in Sf9 cells. The Ac-Bm hybrid virus harboring GFP was named as Ac-Bm hybrid virus-GFP. The Ac-Bm hybrid virus-GFP-infected insect cells were easily selected by detecting the emission of GFP from each well of cell culture dish on the UV illuminator. GFP produced by Ac-Bm hybrid virus-GFP in Sf9 and Bm5 cells or B. mori larvae was confirmed by SDS-PAGE and Western blot analysis using GFP antibody. In addition, B. mori larvae infected with Ac-Bm hybrid virus-GFP was apparently appeared fluorescence from the whole body at S days postinoculation. The fluorescence of GFP from the hemolymph and fat body of B. mori larvae infected with Ac-Bm hybrid virus-GFP was also observed by fluorescence microscope. In conclusion, our results demonstrated that in baculovirus expression vector system, use of Ac-Bm hybrid virus have an additional advantage of expanded host range for producing recombinant proteins.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.82-83
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• 2003

In previous experiment, we reported when the heterologous protein is expressed by using baculovirus expression vector system (BEVS), although the amount of intracellular protein is abundant, the amount of extracellular Protein is poor. As the link in the chain of the research, we investigated the secretory pathway, important in case of the secretory protein, of the protein expressed in insect cells using BEVS. (omitted)

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.19-26
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• 2001

Transformed Spodoptera frugiperda (Sf9) cells expressing baculovirus very late factor (VLF-1) were constructed by using Autograha nuclear polyhedrosis virus (AcNPV) immediate earthy gene (ie1). Neomycin-resistance gene as a selectable marker was introduced under the control of AcNPV ie1 promoter, and Bombyx mori nuclear polyhedrosis (BmNPV-K1) vlf-1 gene was introduced under the control of the Drosophila heat shock protein gene (hspr70) promoter to yield dual expression plasmid with two independent transcription units. It was transfected into Sf9 cells and cell clones expressing vlf-1 were selected by G4l8 treatment. Genomic DNA from transformed cells was isolated and integration of AcNPV iel harboring vlf-1 was confirmed by PCR using AcNPV iel-specific primers and Southern blot analysis. The transformed cells expressing VLF-1 in an infection-independent manner expressed foreign gene product of recombinant baculovirus in the earlier stage of infection compared with control Sf9 cells. These results suggest the possible to develop highly efficient transformed insect cells for baculovirus expression vector system.

• International Journal of Industrial Entomology and Biomaterials
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• 제1권1호
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• pp.53-58
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• 2000

A cDNA encoding the luciferase of firefly Luciola lateralis was cloned downstream from the polyhedrin gene promoter of Bombyx mori nucleopolyhedrovirus and expressed in B. mori cells (BmN-4). The coding soquence for luciferase was inserted into pBmKSK2 rectors) which was reconstructed from the polyhedrin-based transfer vector pBmKSKl by modifying cloning sites. Recombinant virus, BmK2-LUCDF, containing the luciferase gene was selected and purified in BmN-4 cells. The emission of luminescence by luciferase was only detected in BmK2-LUCDF-infected cell extracts. This result indicates that the cloned new luciferase gene of firefly L. lateralis can be expressed efficiently in baculovirus expression system and used as a useful reporter gene.