• BMB Reports
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• 제40권1호
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• pp.65-71
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• 2007

The Helicoverpa armigera nucleopolyhedrovirus (HearNPV) ORF80 (ha80) has 765 bp encoding a protein with approximately 254 amino acids and a predicted molecular weight of 30.8 kDa. Homologues of ha80 are found in most baculovirus sequences, including those from lepidopteran NPVs, lepidopteran granuloviruses (GVs), hymenopteran baculoviruses, and one dipteran baculovirus, yet their functions remain unclear. In this study we characterized ha80, and showed that it was transcribed late in infected host cells (HzAM1). The product of ha80 was a 31 kDa protein that was not a structural protein of budded virus (BV) or occlusion-derived virus (ODV) particles. Ha80 was first detected in the cytoplasm of infected HzAM1 cells at 12 h p.i., and was observed in the nucleus at later stages of infection, suggesting that it may be involved in transporting viral proteins into the host cell nucleus or play its roles in the nucleus.

• 대한의생명과학회지
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• 제16권3호
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• pp.201-206
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• 2010

In order to develop procedures for the rapid isolation of recombinant sugar transporter in functional form from away from the endogenous insect cell transporter, gene fusion techniques were exploited. Briefly, BamH1-digested human HepG2 type glucose transport protein cDNA was first cloned into a transfer vector pBlueBacHis, containing a tract of six histidine residues. Recombinant baculoviruses including the human cDNA were then generated by allelic exchange following transfection of insect cells with wild-type BaculoGold virus DNA and the recombinant transfer vector. Plaque assay was then performed to obtain and purify recombinant viruses expressing the human transport protein. All the cell samples that had been infected with viruses from the several blue plaques exhibited a positive reaction in the immnuassay, demonstrating expression of the glucose transport protein. In contrast, no color development in the immunoassay was observed for cells infected with the wild-type virus or no virus. Immunoblot analysis showed that a major immunoreactive band of apparent Mr 43,000~44,000 was evident in the lysate from cells infected with the recombinant baculovirus. Following expression of the recombinant fusion protein with the metal-binding domain and enterokinase cleavage site, the fusion protein was recovered by competition with imidizole using immobilized metal charged resin. The leader peptide was then removed from the fusion protein by cleavage with porcine enterokinase. Final separation of the recombinant protein of the interest was achieved by passage over $Ni^{2+}$-charged resin under binding conditions. The expressed transport protein bound cytochalasin B and demonstrated a functional similarity to its human counterpart.

• 대한바이러스학회지
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• 제27권2호
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• pp.239-255
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• 1997

전염성 췌장괴저바이러스 (Infectious pancreatic necrosis virus) DRT 주의 VP1유전자를 대 장균 발현운반체와 Baculovirus에 삽입하여 대장균과 진핵세로에서 VP1단백질의 발현을 연구하였다. 재조합체 pMal-pol 클론 [7]에서 2.7 Kb 단편인 VP1 유전자를 제한효소 XbaI으로 절단하여 Baculovirus 운반체인 pBacPAK9에 클로닝하여 pBacVP1이라 명명하였다. 이 pBacVP1에 클로닝된 VP1유전자를 제한효소 SacI과 PstI으로 절단하여 대장균 발현 운반체인 pQE-30에 클로닝하여 pQEVP1이라 명명하였다. 또한 VP1 단백질의 C-말단에 6개의 히스티딘 $6{\times}His$이 붙어 있는 단백질을 만들기 위하여, pQEVP1 클론의 His부위를 EcoRI으로 절단하고, 또한 pBacVP1을 EcoRI으로 절단하여 생긴 부위에His-EcoRI DNA 단편을 교체시켜 재클로닝하여 pBacHis-VP1을 만들었다. pBacHis-VP1 DNA와 Bsu36I로 처리된 LacZ-Hyphantria cunea nuclear polyhedrosis virus (LacZ-HcNPV)를 함께 lipofectin을 이용하여 곤충세포 (Spodoptera frugiperda cell)에 동시 감염을 시켜서 재조합 바이러스를 선발하여, VP1-HcNPV-1이라 명명하였다. pQEVP1 클론은 6개의 히스티딘 단편이 부착된 VP1단백질을 Ni-NTA resin 크로마토그래피법으로 정제하여 SDS-PAGE와 Western blot으로 확인하였고, 단백질의 활성과 구조에 영향을 주지 않는 6개의 히스티딘 단편 ($6\;{\times}\;His$)이 부착된 94 kDa의 VP1단백질을 정제할 수 있었다. 또한 재조합 바이러스에 감염된 곤충세포에서 VP1 단백질이 발현된 것을 전기영동과 Western blot으로 검색을 한 결과 95 kDa VP1 단백질이 발현이 되었음을 확인하였다.

• 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.

• 대한바이러스학회지
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• 제28권1호
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• pp.53-62
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• 1998

Human papillomavirus (HPV) 16, E7 proteins derived from the prototype (Bac73) and natural variant (Bac101) E7 open reading frame were produced in Sf9 insect cells. The variant E7 gene occurred naturally by substitution mutation at the position of 88 nucleotide, resulting serine instead of asparagine. Using E7 specific monoclonal antibody (VD6), both E7 proteins were identified in recombinant baculovirus infected SF9 cells. Radiolabelling and immunoprecipitation analysis revealed that both E7 proteins were phosphoproteins. Immunostaining result showed that E7 proteins were mainly localized in the cytoplasm. Nuclear form of E7 proteins was also detected after a sequential fractionation procedure for removing chromatin structure. Considering that the VD6 recognition site in E7 protein is located within 10 amino acid at the N-terminus, this region appears to be blocked by the nuclear component. Western blot analysis revealed that nuclear form was more abundant than cytoplasmic E7 proteins. Time course immunostaining showed that the primary location of E7 protein was the nucleus and exported to the cytoplasm as proteins were accumulated. These events occurred similarly in both Bac73 and Bac101 infected Sf9 cells, suggesting that these two proteins may have similar biological functions.

• 대한바이러스학회지
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• 제29권2호
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• pp.137-144
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• 1999

Transformation efficiency, virus multiplication and foreign gene expression were characterized in the insect cells transformed with Autographa californica nuclear polyhedrosis virus (AcNPV) immediate early 1 gene (IE1). Transformation efficiency of insect cells by AcNPV IE1 gene vector horboring foreign gene was approximately 8-fold higher in the Sf9 cells transformed previously with AcNPV IE1 gene than in the normal Sf9 cells. Virus multiplication and foreign gene expression of recombinant baculovirus in the Sf9 cells transformed with AcNPV IE1 gene were similar to those of the normal Sf9 cells. These results suggest that transformed cells displaying foreign gene product by using AcNPV IE1 gene promoter will be useful for the diverse applications of insect cells.

• 한국잠사곤충학회지
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• 제44권2호
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• pp.64-68
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• 2002

본 연구는 곤충 유전자를 이용한 항세균성 펩타이드 생산 및 농업용 소재로서의 응용에 관한 연구로서 항세균성 단백질 누에신 유전자를 베큘로 바이러스 발현계(BEVS)를 이용하여 곤충세포주에서 발현한 후 누에신 단백질의 농업용 소재로서의 가능성을 모색하기 위해 농작물을 가해하는 감자 고추의 무름병을 일으키는 Pectobacterium carotovorum subsp. carotovorum, 가지 및 고추의 풋마름병을 일으키는 Ralstonia solanacearum, 양송이 버섯의 세균성 갈색 무늬 병을 일으키는 Pseudomonas tolaasii 및 무와 배추의 검은썩음병을 일으키는 Xanthomonas campestris pv. campestris 에 대해서 항세균 활성을 관찰하였다. 그 결과 Pectobacterium carotovorum subsp. carotovorum, Ralstonia solanacearum 및 Pseudomonas tolaasii에 대해 높은 활성을 나타내었으며 Xanthomonas campestris pv. campestris에는 활성을 나타내지 않았다. Ion exchange 및 gel filtration chromatography 를 수행하여 약 20 kDa의 성숙 누에신 단백질을 순수 분리하여 pH 및 온도에 대한 안정성을 조사한 결과, pH 2~12 완충액에서 30분간 처리하였을 때에도 항세균 활성이 그대로 유지되었고 10$0^{\circ}C$에서 2시간 처리시에는 활성이 안정되었으며 4시간 처리시에도 80% 정도로 유지됨을 확인함으로써 누에신 단백질은 pH 및 온도에 대한 안정성이 있음을 확인할 수 있었다.

• 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.

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.307-314
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• 1999

The human muscarinic acetylcholine receptor (mAChR) subtypes Hml, Hm2 and Hm3 have been expressed in insect cells (Spodoptera frugiperda, Sf9) using the baculovirus expression system. Expression of relevant DNA, transcript and receptor proteins was identified by PCR, Northern blotting and [$^{3}H$]QNB binding, respectively. As assessed by [$^{3}H$]QNB binding sites, yields of muscarinic receptors in membrane preparations in this study were as about 5-20 times high as those in mammalian cells reported in previous studies. The [$^{3}H$]QNB competition binding studies with well-known subtype-selective mAChR antagonists showed that the receptors expressed in Sf9 cells retain the pharmacological characteristics expected for the ml , m2 and m3 muscarinic receptors. The ml-selective antagonist, pirenzepine, displayed a considerably higher affinity for Hml by 110-fold and 35-fold than for Hm2 and Hm3, respectively, The m2-selective methoctramine displayed a significantly higher affinity for Hm2 than for Hml and Hm3 (10- and 26-fold, respectively). p-F-HHSiD exhibited high affinity for Hm3 that is not significantly different from those for Hml, but 66-fold higher than its affinity for Hm2. The functional coupling of the recombinant receptors to second messenger systems was also examined. While both Hml and Hm3 stimulated phosphoinositide hydrolysis upon activation by carba-chol, Hm2 produced no response. On the other hand, activation of mAChRs induced the inhibition of forsko-lin-stimulated cyclic AMP formation in Hm2-expressing cells, whereas the significant dose-dependent increase in or poor response on cyclic AMP formation were produced in Hml or Hm3-expressing cells, respectively. These results indicate the differential coupling of recombinant Hml, Hm2 and Hm3 receptors expressed in SF9 cells to intracellular signalling system.

• 대한바이러스학회지
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• 제26권2호
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• pp.173-179
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• 1996

The gene encoding gIII of bovine herpesvirus type 1 (BHV-1) PQ strain was cloned and expressed in baculovirus. Although the gIII gene is located in Hind III I fragment as the case of the other BHV-1 strains, differences in size and restriction endonuclease site within the fragment were identified. The gIII expression was predominantly detected on the surface on insect cells by indirect immunofluoresecnce assay using monoclonal antibody. The western blotting analysis also revealed the presence of expressed protein of a similar molecular size to the original gIII protein. The immunogenicity of expressed protein were tested in guinea pigs. The immunized guinea pigs with expressed protein developed the neutralizing antibodies against BHV-1.