• 한국수정란이식학회지
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• 제14권1호
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• pp.3-5
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• 1999

이식 전 수정란의 성판정은 많은 축산인의 소망이었다. 많은 방법이 제기되었지만, 세포유전학적 분석방법은 ET의 상용화에 거의 무의미할 정도로 한계가 많았고, 이후 개발된 응성 특이적 항원이나 X-염색체에서 발현되는 효소의 활동을 통한 성판정 방법은 흥미롭기는 하나 산업적 적용에 제약이 많았다. 80년대 중반 Y-염색체 특이적인 DNA 탐침자의 개발과 PCR을 통한 DNA증폭기술의 개발은 수정란 성판정을 획기적으로 개선시켰다. DNA기술을 통한 수정란의 성판정은 분자생물학을 현장으로 진출시킨 첫 경우이기도 했다. 90년대에 세포유전학적 분석에서 FISH가 소개되었으며, 염색체 특이적 library는 다른 기초적이고 응용세포유전학적 연구에 유용한 도구가 되었다. 최근에는 사람에서는 착상전 수정란의 성판별 및 유전진단을 위해 실시되고 있는 형광직접접합법(fluorescent in situ hybridization, FISH)은 효소적 유전자 증폭(polymerase chain reaction; PCR)에 비해 높은 민감도와 정확성을 보이고 있으나 hybridization 및 washing 과정에 매우 긴 시간이 소요되고, 절차도 까다로워 현장에서의 적용이 용이치 않았다. 그러나 direct labelled probe의 이용, heat programmable instrument의 개발, denaturing chemical의 사용배제 등을 통해 소요시간 및 절차의 대폭적인 간소화를 이루어 현장의 적용 가능성을 한층 높이고 있다. 현재 사람의 세포유전학 및 종양학에서는 FISH의 다양한 기술이 많이 이용하고 있으나 소에서는 탐침자(probe)가 개발되어 있지 않아 그 이용이 미미하다. 본 연구는 FISH를 이용하기 위한 탐침자의 개발을 궁극적인 목표로 삼았으며, 이를 위해 접근이 용이한 방식을 개발하여 기존의 방식과는 다른 소 배아세포의 성을 판별 할 수 있는 접근방법을 소개 하고자한다.

• Mass Spectrometry Letters
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• 제10권3호
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• pp.93-101
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• 2019

Algorithms and software for predicting tandem mass spectra have been developed in recent years. In this work, we explore how distinct in silico $MS^2$ spectra are predicted for isomers, i.e. compounds having the same formula and similar molecular structures, to differentiate between them. We used the CFM-ID 2.0/3.0 predictor with regard to (a) test compounds, whose experimental mass spectra had been randomly sampled from the MassBank of North America (MoNA) collection, and to (b) the most widespread isomers of test compounds searched in the PubChem database. In the first validation test, in silico mass spectra constitute a reference library, and library searches are performed for test experimental spectra of "unknowns". The searches led to the true positive rate (TPR) of ($46-48{\pm}10$)%. In the second test, in silico and experimental spectra were interchanged and this resulted in a TPR of ($58{\pm}10$)%. There were no significant differences between results obtained with different metrics of spectral similarity and predictor versions. In a comparison of test compounds vs. their isomers, a statistically significant correlation between mass spectral data and structural features was observed. The TPR values obtained should be regarded as reasonable results for predicting tandem mass spectra of related chemical structures.

• BMB Reports
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• 제53권3호
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• pp.166-171
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• 2020

A chemical library comprising 2,354 drug-like compounds was screened using a transcription and replication-competent viruslike particle (trVLP) system implementing the whole Ebola virus (EBOV) life cycle. Dose-dependent inhibition of Ebola trVLP replication was induced by 15 hit compounds, which primarily target different types of G protein-coupled receptors (GPCRs). Based on the chemical structure, the compounds were divided into three groups, diphenylmethane derivatives, promazine derivatives and chemicals with no conserved skeletons. The third group included sertindole, raloxifene, and ibutamoren showing prominent antiviral effects in cells. They downregulated the expression of viral proteins, including the VP40 matrix protein and the envelope glycoprotein. They also reduced the amount of EBOV-derived tetracistronic minigenome RNA incorporated into progeny trVLPs in the culture supernatant. Particularly, ibutamoren, which is a known agonist of growth hormone secretagogue receptor (GHSR), showed the most promising antiviral activity with a 50% effective concentration of 0.2 μM, a 50% cytotoxic concentration of 42.4 μM, and a selectivity index of 222.8. Here, we suggest a strategy for development of anti-EBOV therapeutics by adopting GHSR agonists as hit compounds.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1430-1435
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• 2020

Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is Komagataeibacter xylinus. However, due to limited tools of expression, this host is difficult to engineer metabolically to improve BC productivity. In this study, a regulated expression system for K. xylinus with synthetic ribosome binding site (RBS) was developed and used to engineer a BC biosynthesis pathway. A synthetic RBS library was constructed using green fluorescent protein (GFP) as a reporter, and three synthetic RBSs (R4, R15, and R6) with different strengths were successfully isolated by fluorescence-activated cell sorting (FACS). Using synthetic RBS, we optimized the expression of three homologous genes responsible for BC production, pgm, galU, and ndp, and thereby greatly increased it under both static and shaking culture conditions. The final titer of BC under static and shaking conditions was 5.28 and 3.67 g/l, respectively. Our findings demonstrate that reinforced metabolic flux towards BC through quantitative gene expression represents a practical strategy for the improvement of BC productivity.

• 한국컴퓨터정보학회논문지
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• 제27권9호
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• pp.139-147
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• 2022

본 연구에서는 증강현실 기술을 이용하여, 화학에 입문하는 사람이 화학 학습에 필요한 지식을 쉽게 습득할 수 있도록 모바일 애플리케이션을 개발하는 것을 목표로 한다. 본 연구에서는 2차원 형태의 그림을 인식해 화학 구조를 3차원의 개체로 증강 시켜 사용자의 화면에 보여주고, 이와 관련된 다분야의 정보를 동시에 제공하는 서비스를 활용해 새로운 화학 학습 경험을 제공하는 점이 특징이다. 이를 위해 별도의 시스템과 콘텐츠를 구성하였고, 안전하고 실시간적인 데이터 관리를 위해 로그인 API와 실시간 데이터베이스 기술을 사용하였으며, 이미지 인식 및 3차원 개체 증강 서비스를 위해 이미지 트래킹 기술을 사용하였다. 본 연구를 통한 결과는 실험을 통해 유의미한 결과를 도출하였다. 향후 연구에서는 화학 구조 데이터 라이브러리를 사용하여 효율적으로 데이터를 불러오고 출력할 수 있도록 한다.

• 한국분말재료학회지
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• 제15권5호
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• pp.399-404
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• 2008

Spray pyrolysis was applied to prepare $M_{3}MgSi_{2}O_{8}:Eu^{2+}$ (M=Ca, Sr, Ba) blue phosphor powder. The library of a Ca-Sr-Ba ternary system was obtained by a combinatorial method combined with the spray pyrolysis in order to optimize the luminescent property under vacuum ultraviolet (VUV) excitation. 10 potential compositions were chosen from the first screening. The emission shifted to longer wavelength as Ca became a dominant element and the emission intensity was greatly reduced in the composition region at which Ba is dominant element. On the base of the first screening result, the second fine tuning was carried out in order to optimize the luminescence intensity under VUV excitation. The optimal composition for the highest luminescence intensity was $(Ca_{1.7},\;Sr_{0.3},\;Ba_{1.0})Si_{2}O_{8}:Eu^{2+}$ which had the color coordinate of (0.152, 0.072) and about 64% emission intensity of $BaMgAl_{10}O_{17}$ (BAM) phosphor.

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.2033-2037
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• 2005

In vitro selection was used to isolate $Mg^{2+}$-dependent self-cleaving ribozymes with cis-cleavage activity from a pre-tRNA library having 40-mer random sequences attached to 5'-end of E. coli $tRNA^{Phe}$. After 8 rounds of SELEX (Systematic Evolution of Ligands by Exponential Enrichment), RNA molecules which can self-cleave at the high concentration of $Mg^{2+}$ were isolated. The selected ribozymes can carry out the self-cleavage reaction in the presence of 100 mM $Mg^{2+}$ but not in 10 mM $Mg^{2+}$. The cleavage sites of the ribozymes are located at +3 and +4 of $tRNA^{Phe}$, compared with +1 position of 5'-end cleavage site of pre-tRNA by RNase P. New RNA constructs deprived of its D stem-loop, anticodon stem-loop, variable loop and T stem-loop, respectively showed the cleavage specificity identical to a ribozyme having the intact tRNA structure. Also, the new ribozyme fused with both a ribozyme and $tRNA^{Leu}$ showed the cleavage activities at the various sites within its sequences, different from two sites of position +3 and +4 observed in the ribozyme with $tRNA^{Phe}$. Our results suggest that the selected ribozyme is not structural-specific for tRNA.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.29-34
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• 2001

The mutant enzymes of N-carbamyl-D-amino aicd amidohydrolase (N-carbamylase) from Agrobacterium radiobacter NRRL B11291, showing a negligible activity, were selected from the library generated by random mutagenesis. From the sequence analysis, these mutants were found to contain the amino acids substitutions at Cys172, Glu47, and Glu146. Previously, Cys172 was reported to be necessary for the enzyme catalysis. The chemical modification of the N-carbamylase by carboxyl group specific chemical reagent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide(EDC), resulted in a loss of activity. The replacement of glutamic acids with glutamines by site-directed mutagenesis led to aggregation of the enzymes. Mutant enzymes fused with maltose binding protein (MBP) were expressed in soluble form, but were inactive. These results indicate that two glutamic acid residues play an important role in structure and function of the N-carbamylase. Multiple sequence alignment of the related enzymes revealed that Glu47 and Glu146 are rigidly conserved, which suggests that tese residues are crucial for the structure and function of the functionally related C-N hydrolases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.92-92
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• 2018

Silene seulensis Nakai was used as traditional medicines in Korea, we collected plant from demilitarized zone (DMZ). S. seulensis was extracted with 30, 50, and 70% ethanol and partitioned successively with n-hexane, EtOAc, dichloromethane and BuOH. These extracts (30, 50 and 70% ethanol) were evaluated the cytotoxicity on B16F10 and Hacat cell lines. The LC-MS/MS data of each fractions (n-hexane, EtOAc, dichloromethane, and BuOH) were compared with MS library, combined with ultraviolet/visual (UV/Vis) and MS data for faster determine structure by database search results. This led to the identification of four compounds (1-4) from S. seulensis. These compounds was isolated first time from S. seulensis. Their chemical structures are elucidated by combinations of NMR and mass spectrometry techniques.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2627-2632
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• 2010

Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSL-homolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at $2.2\;{\AA}$ resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external ${beta}8$-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSL-homolog proteins.