• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.236-242
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• 2002

Using agarose-coupled methotrexate, we have successfully isolated two proteins, which have strong interactions with methotrexate. The two proteins were analyzed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and identified as carbamoyl-phosphate synthetase 2 and phosphoribosylglycinamide formyltransferase, respectively. Interestingly, both of these two proteins are essential key enzymes in nucleotide biosynthetic pathways, like dihydrofolate reductase, a well-known methotrexate target. We confirmed the specificity of their interactions between methotrexate and two target proteins by the methods of competition binding assay, which were followed by western blotting using antibody against carbamoyl-phosphate synthetase 2 and phosphoribosylglycinamide formyltransferase, respectively. Moreover, we could observe that carbamoyl-phosphate synthetase 2 is overexpressed in methotrexate-resistant MOLT-3 cells comparing with control MOLT-3 cells. This result indicates that carbamoyl-phosphate synthetase 2 may be a novel target of methotrexate in cancer therapy. We propose that chemical proteomics can be a powerful technique to identify target proteins of a chemical.

• Journal of Korean Neurosurgical Society
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• 제48권1호
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• pp.8-13
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• 2010

Objective : The etiology and pathogenesis of moyamoya disease remain unclear. Furthermore, the definitive diagnostic protein-biomarkers for moyamoya disease are still unknown. The present study analyzed serum proteomes from normal controls and moyamoya patients to identify novel serological biomarkers for diagnosing moyamoya disease. Methods : We compared the two-dimensional electrophoresis patterns of sera from moyamoya disease patients and normal controls and identified the differentially-expressed spots by matrix-assisted laser desorption/ionization-time-of flight mass spectrometry and electrospray ionization quadruple time-of-flight mass spectrometry. Results : We found and analyzed 22 differently-expressed proteomes. Two proteins were up-regulated. Twenty proteins were down-regulated. Complement C1 inhibitor protein and apolipoprotein C-III showed predominantly changed expressions (complement C1 inhibitor protein averaged a 7.23-fold expression in moyamoya patients as compared to controls, while apolipoprotein C-III averaged a 0.066-fold expression). Conclusion : Although our study had a small sample size, our proteomic data provide serologic clue proteins for understanding moyamoya disease.

• 분석과학
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• 제25권2호
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• pp.114-120
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• 2012

펩타이드의 정성 분석에서, O-Methylisourea는 펩타이드의 특정 아미노산(예. 라이신)에 화합결합하여 해당 펩타이드의 신호를 증진시키기 때문에 펩타이드를 matrix-assisted laser desorption/ionizationmass spectrometry (MALDI-MS) 분석하기 위해 흔히 사용되는데, 이러한 과정은 guanidination이라고 불린다. Guanidination은 반응 조건에 따라 효율이 변하게 된다. 본 연구에서는 트립신으로 가수분해된 미오글로빈 단백질을 세 가지 다른 반응시약 (O-methylisourea, S-methylisothiourea, 2-methyl-2-imidazoline)을 사용하여 $65^{\circ}C$ 에서 1 시간 동안 다양한 pH 조건 (pH 4.0, 7.0 및 10.5)에서 guanidination 반응을 수행하였는데, 실험 결과 O-methylisourea와 pH 10.5이 가장 좋은 효율을 나타내었다. 다음으로 O-methylisourea와 pH 10.5의 반응 조건을 이용하여 열, 마이크로파, 초음파 등과 같은 다양한 조건에서 시간을 변화시켜 가면서 guanidination을 연구하였는데, 열을 이용하여 60 분 동안 반응시키는 것이 가장 효과적이었다. 결론적으로 O-methylisourea을 이용하여 pH 10.5 용액에서 열을 이용하여 1 시간 동안 $65^{\circ}C$에서 가열하는 것이 guanidination을 위한 최적의 조건이었다.

• Molecules and Cells
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• 제22권1호
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• pp.36-43
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• 2006

Mesenchymal stem cells (MSCs) are promising candidates for cell therapy and tissue engineering, but their application has been impeded by lack of knowledge of their core biological properties. In order to identify MSC-specific proteins, the hydrophobic protein fraction was individually prepared from two different umbilical cord blood (UCB)-derived MSC populations; these were then subjected to two-dimensional (2D) gel electrophoresis and peptide mass fingerprinting matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF)-mass spectrometry (MS). Although the 2D gel patterns differed somewhat between the two samples, computer-assisted image analysis identified shared protein spots. 35 spots were reliably identified corresponding to 32 different proteins, many of which were chaperones. Based on their primary sub-cellular locations the proteins could be grouped into 6 categories: extracellular, cell surface, endoplasmic reticular, mitochondrial, cytoplasmic and cytoskeletal proteins. This map of the water-insoluble proteome may provide valuable insights into the biology of the cell surface and other compartments of human MSCs.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.219-222
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• 2000

Physiological changes of Escherichia coli during the fed-batch fermentation process were characterized in this study. Overall cellular protein samples prepared at the different stage of fermentation were separated by 2-dimensional gel electrophoresis (2-DE), and differently expressed 15 proteins, Phosphotransferase enzyme I, GroEL, Trigger factor, ${\beta}$ subunit of ATP synthase, Transcriptional regulator KDGR, Phosphoglycerate mutase 1, Inorganic pyrophosphatase, Serine Hydroxymethyl-transferase, ${\alpha}$ subunit of RNA polymerase, Elongation factor Tu, Elongation factor Ts, Tyrosine-tRNA ligase, DnaK suppressor protein, Transcriptional elongation factor, 30S ribosomal protein S6 were identified using matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS). When bacterial cells grow to high cell density, and IPTG-inducible heterologous protein is produced, expression level of overall cellular proteins was decreased. According to their functions in the cell, identified proteins were classified into three groups, proteins involved in transport process, small-molecule metabolism, and synthesis and modification of macromolecules.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.197-197
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• 2004

The purpose of this experiment was to investigate the protein profiles in the placenta of Korean native cows(KNC) transferred cloned embryos and KNC artificially inseminated placental tissues were collected from the cows after cesarean section around parturition, and placental proteins were analyzed. Using two dimensional polyacrylamide gel eletrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. (omitted)

• Biomolecules & Therapeutics
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• 제13권4호
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• pp.240-245
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• 2005

An antimicrobial molecule was purified from centipede, Scolopendra subspinipes mutilans L. Koch, by reverse phase-HPLC. Its molecular weight was determined to be 1208.5493 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Total amino acid composition analysis revealed that it consists of E, G, P, V, L, F, and W. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram-positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin resistant enterococci (VRE). It may be a useful molecule for a new antibiotic development, especially against drug-resistant bacteria. We suggest that it may playa role in the defense system of this animal. This is the first report of a peptidic antimicrobial substance from centipede.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.253-259
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• 2008

Human follicular fluid (HFF) is the in vivo microenvironment for oocyte maturation and includes a variety of proteins that could be involved in oocyte development and fertilization. We therefore used a proteomic approach to identify new HFF proteins. HFF from mature human follicles was obtained from five women following oocyte collection for in vitro fertilization (IVF). Ethanol-precipitated HFF run on two-dimensional gel electrophoresis (2DE) produced approximately 250 Coomassie brilliant blue-stained spots, 64 of which were identified using matrix-assisted laser desorption/ionization-mass spectrometry (MALDIMS). In this study, several proteins including complement factor H, inter-${\alpha}$ (globulin) inhibitor H4, inter-${\alpha}$-trypsin inhibitor heavy chain H4 precursor, human zinc-${\alpha}$-2-glycoprotein chain B, PRO2619, PRO02044, and complex-forming glycoprotein HC were new proteins that have not been previously reported in HFF using proteomic methods. Additionally, we identified alloalbumin venezia for the first time from trichloroacetic acid (TCA)-precipitated HFF. These HFF proteins could serve as new biomarkers for important human reproductive processes.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 추계학술발표회 요지
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• pp.280-281
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• 2005

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.354-357
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• 2017

There is an increase in the presence of drug-resistant staphylococci outside of the nosocomial and healthcare setting. Although the presence of staphylococci has been studied in several public spaces, nothing is known on the presence of staphylococci in public libraries. Book surfaces from public libraries in the East London area, United Kingdom were swabbed and cultured and identity of the isolates determined by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS). Seven different staphylococcal species were identified by MALDI-TOF-MS analysis. This short study provides evidence of the presence of multidrug-resistant staphylococci in public libraries in the East London area.