• 식물조직배양학회지
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• 제24권5호
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• pp.305-311
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• 1997

Bacillus thuringiensis는 그람 양성 토양 세균으로 포자형성시 결정화된 내포체를 형성하는데, 이 내포체를 구성하는 결정단백질은 각 곤충에 대하여 특이적인 독성을 나타낸다. 살충성 결정단백질 중 Cry II A 결정단백질은 인시류와 쌍시류 곤충에 모두 특이적으로 작용한다. 결정단백질은 살충제로서 불안정하고 포장에서 지속성이 낮은 단점을 가지고 있으므로, 본 연구에서는 Cry II A 결정단백질 유전자가 형질전환된 담배 식물을 제작하고자 하였다. cry IIA 유전자가 삽입된 벡터를 대장균에 형질전환한 후, 알칼리 용액에 대한 용해도의 차이를 이용하여 Cry II A 결정단백질(70 kDa)을 분리하였고, 분리한 Cry II A 결정단백질을 trypsin 처리하여 활성화된 Cry II A (50 kDa)를 확인하였다. 식물 형질전환을 위하여 두 개의 CaMV 35S promoters에 의해 발현이 조절되는 식물 발현 벡터에 cry II A 유전자를 클로닝 하였다. 이 식물 발현 벡터를 Agrobacterium을 이용한 엽편형질 전환을 통해 담배(N. tabacum var. Petit Havana SRI)에 형질전환 시켰으며, 재분화 과정을 거쳐 여섯 개체의 형질전환 식물체를 얻었다. Southern blot을 통하여 분석한 결과 세 개체 내에 cry II A 유전자가 존재하였는데, 한 개체에는 하나의 cry II A 유전자가, 또 한 개체에는 두 개의 cry II A 유전자가, 다른 한 개체에는 잘려진 형태의 cry II A 유전자가 존재함을 확인할 수 있었다. 본 연구를 통하여 얻어진 cry II A 형질전환 식물체는 살충성 검정 등을 거친 후 내충성 식물 생산 및 후대 유전 양상 분석을 위한 기초 자료로 이용될 수 있을 것이다.

• BMB Reports
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• 제40권5호
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• pp.783-790
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• 2007

Receptor binding plays an important role in determining host specificity of the Bacillus thuringiensis Cry $\delta$-endotoxins. Mutations in domains II and III have suggested the participation of certain residues in receptor recognition and insect specificity. In the present study, we expressed the cloned domain II-III fragment of Cry4Ba and examined its binding characteristics to mosquito-larval midgut proteins. The 43-kDa Cry4Ba-domain II-III protein over-expressed in Escherichia coli as inclusion bodies was only soluble when carbonate buffer, pH 10.0 was supplemented with 4M urea. After renaturation via stepwise dialysis and subsequent purification, the refolded domain II-III protein, which specifically reacts with anti Cry4Ba-domain III monoclonal antibody, predominantly exists as a $\beta$-sheet structure determined by circular dichroism spectroscopy. In vitro binding analysis to both histological midgut tissue sections and brush border membrane proteins prepared from susceptible Aedes aegypti mosquito-larvae revealed that the isolated Cry4Ba-domain II-III protein showed binding functionality comparable to the 65-kDa full-length active toxin. Altogether, the data present the 43-kDa Cry4Ba fragment comprising domains II and III that was produced in isolation was able to retain its receptor-binding characteristics to the target larval midgut proteins.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.199-204
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• 2009

The newly cloned Bacillus thuringiensis cry1-5 gene showed high activity to both Plutella xylostella and Spodoptera exigua, while cry1Ac only showed high activity against P. xylostella but low to S. exigua. Through the alignment of amino acid sequences between Cry1Ac and Cry1-5, we found 12 different residues in domain I (6 residues) and domain II (6 residues). In this study, the modified cry1Ac gene, which is constructed according to a crop-preferring codon usage, was used as a template to construct mutant B. thuringiensis cry1Ac genes based on cry1-5 gene through multi site-directed mutagenesis. Total 63 various mutant cry genes were obtained at 12 positions randomly. Among them, ten mutant cry genes, whose domain I was totally converted and domain II was randomly, were selected to express in baculovirus expression system as a polyhedrin fusion form. The recombinant proteins were 95 kDa in size and were stably activated as 65 kDa by trypsin. The expressed mutant Cry proteins were applied to bioassays against P. xylostella and S. exigua. All mutants showed high insecticidal activity both to P. xylostella and S. exigua similar to cry1-5. These results suggest that these mutant cry genes might be expected of desirable cry genes for introduction to transgenic crops.

• 한국응용곤충학회지
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• 제36권4호
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• pp.341-350
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• 1997

Autographa californica 핵다각체병 바이러스(AcNPV)의 다각체 단백질과 Bacillus thuringiensis(Bt) cryIA(c) 내독소 단백질의 융합단백질을 생산하는 새로운 재조합 바이러스를 제작하고, 곤충세포주(Spodoptera frugiperda 9)에서 발현된 융합단백질의 특성을 분석하였다. Bt kurstaki HD-73의 cryIA(c) 내독소 단백질 유전자의 N-발단 AcNPV의 완전한 다각체 단백질 유전자의 앞쪽에 융합함에 의하여 또는 다닥체 단백질 유전자내의 제한효소 HindII부위에 삽입함에 의하여 다각체 단백질 유전자의 프로모터 조절하에 도입하였다. 이렇게 작성된 재조합 바이러스를 각각 Btrusl 또는 BtrusII라고 명명하였다. BtrusI은 분명히 단일 전사체를 보임에도 92kDa의 융합 단백질과 다각체 단백질의 두 단백질을 생산하였다. 또한 Btrusl에 의해 만들어진 융합 단백질은 다각체를 형성하지 않았다. 한편, BtrusII에 의해 감염된 곤충세포주에서는 33kDa의 다각체 단백질은 보이지 않았고 단지 융합 단백질만 생산하였으나 다각체는 형성하지 않았다. 따라서 Btrusl에 의해 생산된 융합 단백질의 독성을 조사하기 위하여, Btrusl으로 감염된 곤충세포주를 2령 누에(Bombyx mori)에 접종한 결과 융합 단백질에 의한 독성이 관찰되었다. 결론적으로 다각체 단백질과 Bt cryIA(c) 내독소 단백질에 의한 융합 단백질이 독성을 가지고 있음을 확인하였다.

• Plant Biotechnology Reports
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• 제4권4호
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• pp.293-301
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• 2010

The feasibility of two strategies for transgene pyramiding using Agrobacterium-mediated transformation was investigated to develop a transgenic potato (Solanum tuberosum L. cv. Iwa) with resistance to potato tuber moth (PTM) (Phthorimaea operculella (Zeller)). In the first approach, cry1Ac9 and cry9Aa2 genes were introduced simultaneously using a kanamycin (nptII) selectable marker gene. The second approach involved the sequential introduction (re-transformation) of a cry1Ac9 gene, using a hygromycin resistance (hpt) selectable marker gene, into an existing line transgenic for a cry9Aa2 gene and a kanamycin resistance (nptII) selectable marker gene. Multiplex polymerase chain reaction (PCR) confirmed the presence of the specific selectable marker gene and both cry genes in all regenerated lines. The relative steady-state level of the cry gene transcripts in leaves was quantified in all regenerated lines by real-time PCR analysis. Re-transformation proved to be a flexible approach to effectively pyramid genes for PTM resistance in potato, since it allowed the second gene to be added to a line that was previously identified as having a high level of resistance. Larval growth of PTM was significantly inhibited on excised greenhouse-grown leaves in all transgenic lines, although no lines expressing both cry genes exhibited any greater resistance to PTM larvae over that previously observed for the individual genes. It is anticipated that these lines will permit more durable resistance by delaying the opportunities for PTM adaptation to the individual cry genes.

• 한국잠사곤충학회지
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• 제38권2호
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• pp.154-159
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• 1996

전국 토양, 앙장 농가, 저곡 창고, 시설 원예 단지, 과수원, 산, 밭 등에서 분리한 토양과 먼지 등의 시료로부터 거세미나방속 해충에 강한 독성을 보이는 7개 균주를 분류하였다. 이들을 각각 STB-1에서 STB-7까지 명명하였으며 모두 약 130kDA의 내독소 단백질을 형성하였다. 편모항원성 검정 결과 STB-1, STB-2는 B. thuringiensis subsp. kurstaki와 STB-3, STB-4, STB-5는 subsp. kenyae와 반응하였으며 STB-6, STB-7은 기존의 편모항체와 반응하지 않았다. PCR로 유전자형을 분석한 결과 STB-1은 B. thuringiensis subsp. kurastaki에서는 보고되지 않은 cryIE 유전자를 가지고 있으며 STB-5는 subsp. kenyae와는 다른 유전자형을 보였다. 기존의 편모항체와 반응을 보이지 않은 STB-6와 STB-7은 cryIA(a), cryIA(b), cryIC, cryII를 가지고 있었다.

• Journal of Microbiology and Biotechnology
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• 제23권8호
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• pp.1107-1115
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• 2013

The Cyt1Aa protein of Bacillus thuringiensis susbp. israelensis elaborates demonstrable toxicity to mosquito larvae, but more importantly, it enhances the larvicidal activity of this species Cry proteins (Cry11Aa, Cry4Aa, and Cry4Ba) and delays the phenotypic expression of resistance to these that has evolved in Culex quinquefasciatus. It is also known that Cyt1Aa, which is highly lipophilic, synergizes Cry11Aa by functioning as a surrogate membrane-bound receptor for the latter protein. Little is known, however, about whether Cyt1Aa can interact similarly with other Cry proteins not primarily mosquitocidal; for example, Cry2Aa, which is active against lepidopteran larvae, but essentially inactive or has very low toxicity to mosquito larvae. Here we demonstrate by ligand binding and enzyme-linked immunosorbent assays that Cyt1Aa and Cry2Aa form intermolecular complexes in vitro, and in addition show that Cyt1Aa facilitates binding of Cry2Aa throughout the midgut of C. quinquefasciatus larvae. As Cry2Aa and Cry11Aa share structural similarity in domain II, the interaction between Cyt1Aa and Cry2Aa could be a result of a similar mechanism previously proposed for Cry11Aa and Cyt1Aa. Finally, despite the observed interaction between Cry2Aa and Cyt1Aa, only a 2-fold enhancement in toxicity resulted against C. quinquefasciatus. Regardless, our results suggest that Cry2Aa could be a useful component of mosquitocidal endotoxin complements being developed for recombinant strains of B. thuringiensis subsp. israelensis and B. sphaericus aimed at improving the efficacy of commercial products and avoiding resistance.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5725-5728
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• 2012

Growing evidence shows that deregulation of the circadian clock plays an important role in the development of malignant tumors, including gliomas. However, the molecular mechanisms of gene chnages controlling circadian rhythm in glioma cells have not been explored. Using real time polymerase chain reaction and immunohistochemistry techniques, we examined the expression of two important clock genes, cry1 and cry2, in 69 gliomas. In this study, out of 69 gliomas, 38 were cry1-positive, and 51 were cry2-positive. The expression levels of cry1 and cry2 in glioma cells were significantly different from the surrounding non-glioma cells (P<0.01). The difference in the expression rate of cry1 and cry 2 in high-grade (grade III and IV) and low-grade (grade 1 and II) gliomas was non-significant (P>0.05) but there was a difference in the intensity of immunoactivity for cry 2 between high-grade gliomas and low-grade gliomas (r=-0.384, P=0.021). In this study, we found that the expression of cry1 and cry2 in glioma cells was much lower than in the surrounding non-glioma cells. Therefore, we suggest that disturbances in cry1 and cry2 expression may result in the disruption of the control of normal circadian rhythm, thus benefiting the survival of glioma cells. Differential expression of circadian clock genes in glioma and non-glioma cells may provide a molecular basis for the chemotherapy of gliomas.

• BMB Reports
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• 제37권3호
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• pp.304-313
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• 2004

Three-dimensional (3D) models for the 65-kDa activated Cry4A and Cry4B $\delta$-endotoxins from Bacillus thuringiensis subsp. israelensis that are specifically toxic to mosquito-larvae were constructed by homology modeling, based on atomic coordinates of the Cry1Aa and Cry3Aa crystal structures. They were structurally similar to the known structures, both derived 3D models displayed a three-domain organization: the N-terminal domain (I) is a seven-helix bundle, while the middle and C-terminal domains are primarily comprise of anti-parallel $\beta$-sheets. Circular dichroism spectroscopy confirmed the secondary structural contents of the two homology-based Cry4 structures. A structural analysis of both Cry4 models revealed the following: (a) Residues Arg-235 and Arg-203 are located in the interhelical 5/6 loop within the domain I of Cry4A and Cry4B, respectively. Both are solvent exposed. This suggests that they are susceptible to tryptic cleavage. (b) The unique disulphide bond, together with a proline-rich region within the long loop connecting ${\alpha}4$ and ${\alpha}5$ of Cry4A, were identified. This implies their functional significance for membrane insertion. (c) Significant structural differences between both models were found within domain II that may reflect their different activity spectra. Structural insights from this molecular modeling study would therefore increase our understanding of the mechanic aspects of these two closely related mosquito-larvicidal proteins.

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권1호
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• pp.29-36
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• 2019

Background: An inability to cope with threatening dental stimuli, i.e., sight, sound, and sensation of airotor, manifests as anxiety and behavioral management problems. Behavior modification techniques involving pre-exposure to dental equipment will give children a first-hand experience of their use, sounds, and clinical effects. The aim of this study was to compare the techniques of Tell-Show-Play-doh, a smartphone dentist game, and a conventional Tell-Show-Do method in the behavior modification of anxious children in the dental operatory. Methods: Sixty children in the age group of 4-8 years, with Frankl's behavior rating score of 2 or 3, requiring Class I and II cavity restorations were divided into three groups. The groups were Group 1: Tell-Show-Play-doh; Group 2: smartphone dentist game; and Group 3: Tell-Show-Do technique and each group comprised of 20 children. Pulse rate, Facial Image Scale (FIS), Frankl's behavior rating scale, and FLACC (Face, Leg, Activity, Cry, Consolability) behavior scales were used to quantify anxious behavior. Operator compliance was recorded through a validated questionnaire. Results: The results showed lower mean pulse rates, lower FIS and FLACC scores, higher percentage of children with Frankl's behavior rating score of 4, and better operator compliance in both the Tell-Show-Play-doh and smartphone dentist game groups than in the conventional Tell-Show-Do group. Conclusion: The Tell-Show-Play-doh and smartphone dentist game techniques are effective tools to reduce dental anxiety in pediatric patients.