• 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.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권2호
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• pp.119-123
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• 2013

The insect baculovirus expression vector system (BEVS) is useful for producing biologically active recombinant proteins. However, the overexpression of heterologous proteins using this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we developed a versatile baculovirus expression and secretion system using Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion was found to improve the secretions and antibacterial activities of recombinant nuecin and enbocin proteins. Thus, we conclude that bPDI gene fusion is a useful addition to BEVS for the large-scale production of bioactive recombinant proteins.

• Animal cells and systems
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• 제16권6호
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• pp.455-461
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• 2012

Amongst the various antimicrobial peptides, lysozyme plays a central role in initiating and maintaining the antibacterial defense response of insect. Here we propose the biosynthesis and refolding of recombinant lysozyme in Escherichia coli expressed in inclusion body form. The Agrius lysozyme gene was amplified using gene specific primers and then ligated into the pGEX-4T-1 vector, which contained the glutathione S-transferase (GST) gene as a fusion partner. A recombinant lysozyme was expressed in E. coli Rosetta cells using a pGEX-4T-1 expression vector, and the fusion protein was induced by ioporpyl-${\beta}$-D-thiogalactopyranoside (IPTG). The recombinant protein produced as an inclusion body was resolubilized in solubilization buffer, and the resultant solution was dialyzed in refolding buffer. After thrombin cleavage, the recombinant lysozyme was purified by ion exchange chromatography and reverse phase chromatography. The recombinant lysozyme was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and immunoreactivity against the anti-Agrius lysozyme was observed by western blot analysis of this protein. The recombinant lysozyme displayed antibacterial activity against Bacillus megaterium and Micrococcus luteus, which was confirmed by the inhibition zone assay.

• Biodesign
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• 제7권2호
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• pp.35-37
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• 2019

Xanthomonas oryzae pv. oryzae (Xoo) is a plant pathogen, which causes a bacterial blight of rice. The bacterial blight is one of the most devastating diseases of rice in most of the rice growing countries and there is no effective pesticide against bacterial blight. The β-ketoacyl-acyl carrier protein synthase III (FabH) plays a key role in fatty acid synthesis (FAS) and is a promising drug target for the development of antibacterial agents. Xoo0878 gene, a fabH gene, from Xoo was cloned and its gene product Xoo0878 was expressed, purified and crystallized. Xoo0878 crystal diffracted to 2.1Å resolution and belonged to the triclinic space group P1, with unit-cell parameters a = 57.3Å, b = 64.7Å, c = 104.2Å and α = 81.6°, β = 84.7°, γ = 74.4°. There are four monomers in the asymmetric unit, with a corresponding crystal volume per protein weight of 2.65 ų Da^-1 and a solvent content of 53.6%. Xoo0878 structure will be useful to develop new antibacterial agents against Xoo.

• BMB Reports
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• 제41권5호
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• pp.400-403
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• 2008

The insect baculovirus expression vector system (BEVS) is useful for producing biologically active recombinant proteins. However, the overexpressions of foreign proteins using this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we developed a versatile baculovirus expression and secretion system using Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion was found to improve the secretions and antibacterial activities of recombinant nuecin proteins. Thus, we conclude that bPDI gene fusion is a useful addition to BEVS for the large-scale production of bioactive recombinant proteins.

• 한국응용곤충학회지
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• 제36권4호
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• pp.331-340
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• 1997

곤충 유전자를 이용한 항세균성 펩타이드 생산 및 응용에 관한 기초 연구로서 비병원성 세균(Escherichia coli K12)으로 면역 반응을 유도한 누에로부터 발현량이 증가하는 유전자 중 Hyalophora cecropia의 attacin과 cDNA 상동성을 나타내는 BmInc6 클론을 분리하고 그 특성을 조사하였다. BmInc6 cDNA의 전체염기서열을 분석한 결과 그 크기는 852 bp이고, 35번째 염기에서 변역이 개시되어 679 bp 위치에서 종결되는 open reading frame을 가지며 812번째 위치에 잠정 전사 종결 신호의 존재가 확인되었다(GenBank, AF005384). BmInc6에 의해 coding되는 아미노산은 214개이며, hydropathy 분석 결과 친수성을 나타내는 단백질이었다. 그리고 BmInc6 유전자에 의해 연역되는 펩타이드를 nuecin으로 명명하였다. Nuecin 유전자를 baculovirus 발현 백터계를 이용하여 곤충세포주에서 발현시킨 결과 전사체의 크기는 약 950 bp였고, 세포내 벌현 펩타이드의 분자량은 약 23 kDa이었다. 세포내에서 발현된 nuecin 전구체로 추정되는 23 kDa 펩타이드는 세포외로 분비되는 과정에서 약 3 kDa의 signal 펩타이드가 제거됨으로서 약 20 kDa의 성숙 nuecin으로 된다는 사실을 단백질 전기영동상으로 확인하였다. Nuecin 단백질의 항세균 활성을 수종의 그람 음성 및 양성 세균에 대해 검정한 결과, 특히 E. coli와 Bacillus subtilis에 높은 활성을 나타내었으며, attacin이 한정된 그람 음성 세균에만 항세균 활성을 나타내는데 비해 nuecin은 그람 음성은 물론 그람 양성에도 항세균 활성을 나타내어, 보다 넓은 항세균 스펙트럼을 가지는 것을 알 수 있었다.

• The Plant Pathology Journal
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• 제37권4호
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• pp.389-395
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• 2021

Soil is the major source of plant-associated microbes. Several fungal and bacterial species live within plant tissues. Actinomycetes are well known for producing a variety of antibiotics, and they contribute to improving plant health. In our previous report, Streptomyces globisporus SP6C4 colonized plant tissues and was able to move to other tissues from the initially colonized ones. This strain has excellent antifungal and antibacterial activities and provides a suppressive effect upon various plant diseases. Here, we report the genome-wide analysis of antibiotic producing genes in S. globisporus SP6C4. A total of 15 secondary metabolite biosynthetic gene clusters were predicted using antiSMASH. We used the CRISPR/Cas9 mutagenesis system, and each biosynthetic gene was predicted via protein basic local alignment search tool (BLAST) and rapid annotation using subsystems technology (RAST) server. Three gene clusters were shown to exhibit antifungal or antibacterial activity, viz. cluster 16 (lasso peptide), cluster 17 (thiopeptide-lantipeptide), and cluster 20 (lantipeptide). The results of the current study showed that SP6C4 has a variety of antimicrobial activities, and this strain is beneficial in agriculture.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.223-228
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• 2008

A novel beetle antimicrobial protein from stimulated Copris tripartitus and the corresponding gene were isolated in parallel through differential display-PCR and expression in Escherichia coli. To find cDNA clones responsible for bacteria resistance, the suppression subtractive hybridization and GeneFishing differentially expressed genes system were employed in the dung beetle, Copris tripartitus immunized with lipopolysaccaride. One cDNA clone from eight subtracted clones was selected through dot blot analysis and confirmed by northern blot analysis. The 516-bp, selected cDNA clone was determined by 5' and 3' rapid amplication of cDNA ends and cloned into the GST fusion expression vector pGEX-4T-1 for expression of the protein. The expressed protein was predicted 14.7 kDa and inhibited the growth of gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. These results implied that the expressed protein is related to immune defense mechanism against microorganism.

• 한국잠사곤충학회지
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• 제52권1호
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• pp.45-51
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• 2014

면역 유도된 천잠(Antheraea yamamai) 유충에서 cecropin-A 유전자를 분리하였고 이 유전자를 Ay-CecA로 명명하였다. 전체 Ay-CecA cDNA 크기는 419 bp로 64개의 아미노산 잔기를 인코딩하는 195 bp ORF로 구성되어 있다. 천잠 CecA 유전자는 22개 잔기의 signal peptide, 4개 잔기의 propeptide 및 항균활성을 갖는 37개 잔기로 구성된 성숙 단백질(mature protein) 영역으로 구성되고 예상 분자량은 4046.81 Da으로 산출되었다. 천잠 CecA의 아미노산 서열은 다른 나비목 곤충에서 분리된 cecropin와 매우 높은 상동성(62 ~ 78%)을 나타냈다. Ay-CecA 유전자의 C말단에 기존에 보고된 곤충의 cecropin에서와 동일하게 C말단 아미드화를 위한 glycine 잔기가 존재하고 있다. 이 펩타이드의 항균활성을 검정하기 위해서 대장균 발현 시스템을 이용하여 활성이 있는 재조합 Ay-CecA 발현에 성공하였다. 발현 기주인 대장균에 대한 재조합 CecA 독성 중화를 위해서 불용성 단백질인 ketosteroid isomerase(KSI) 유전자를 CecA 유전자와 융합하였다. 융합 CecA-KSI 단백질은 대부분 불용성 단백질로 발현되었다. 발현된 융합단백질은 Ni-NTA immobilized metal affinity chromatography(IMAC)에 의해서 정제하였으며 CNBr 반응을 통하여 재조합 CecA를 절단하여 용출하였다. 최종적으로 양이온 교환 chromatography 과정을 통하여 CecA를 순수 정제하였다. 정제된 재조합 Ay-CecA는 그람음성균인 E. cori ML 35, Klebsiella pneumonia 및 Pseudomonas aeruginosa에 대해 매우 높은 항균활성을 나타냈었다. 따라서 본 연구 결과, 높은 항균활성 지닌 CecA는 천잠의 면역 반응에서 중요한 역할을 담당할 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제23권2호
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• pp.231-238
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• 2011

Attacin is an insect antibacterial protein that plays an important role in immune response to injury and infection. In this report, we have isolated and characterized of cDNA encoding for the attacin from the immunized larvae of swallowtail butterfly, $Papilio$ $xuthus$. A full length cDNA of $P.$ $xuthus$ attacin was obtained by employing annealing control primer (ACP)-based differential display PCR and 5' RACE. The complete $P.$ $xuthus$ attacin cDNA was comprised of 949 bp encoding a 250 amino acid precursor. It contains a putative 18 amino acid signal peptide sequence, a 42 amino acid propeptide sequence, and a 190 amino acid mature protein with a theoretical molecular mass of 19904.01 and a pI of 9.13. The putative mature protein of $P.$ $xuthus$ attacin showed 48-52% and 24-30% identity in amino acid sequences with that of lepidopteran and dipteran insects, respectively. Semiquantitive RT-PCR results revealed that the transcript of $P.$ $xuthus$ attacin gene was up-regulated at significant levels after injection with bacterial lipopolysaccharide (LPS). We sub-cloned cDNA fragment encoding mature $P.$ $xuthus$ attacin into the expression vector, highly expressed in $E.$ $coli$ BL21 cells, and its antibacterial activity was analyzed. Recombinant $P.$ $xuthus$ attacin evidenced considerably antibacterial activity against Gram-negative bacteria, $E.$ $coli$ ML 35 and $Klebsiella$ $pneumonia$.