• 제목/요약/키워드: time-of-flight (TOF)

검색결과 406건 처리시간 0.025초

백강잠으로부터 분리한 항균물질의 항생제 내성균에 대한 효과 (Effects of an Antimicrobial Substance from Bombycis corpus on Antibiotic Resistant Microbes)

  • 이현우;엄정선;고미경;김미성;은재순;전훈;임재윤
    • 약학회지
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    • 제51권4호
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    • pp.253-258
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    • 2007
  • Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. 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), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

연속에너지 중성자에 대한 천연 Sm의 중성자 포획단면적 측정 (Measurement of Energy Dependent Differential Neutron Capture Cross-section of Natural Sm by Using a Continuous Neutron Flux below)

  • 윤정란
    • 한국방사선학회논문지
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    • 제10권5호
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    • pp.337-341
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    • 2016
  • 중성자에너지 영역 0.003 eV에서 10 eV에 대해 천연 Sm의 Sm(n,${\gamma}$) 반응에 대한 중성자 포획단면적을 측정하였다. 교토대학교 원자로실험소의 46-MeV 전자선형가속기에서 발생되는 전자의 광핵반응에 의한 중성자를 사용하였고 TOF 방법으로 측정하였다. 사용한 검출기는 12개의 BGO($Bi_4Ge_3O_{12}$) 섬광체로 구성되었고 이 검출장치로 Sm(n,${\gamma}$) 반응으로부터 나오는 즉발감마선을 측정하였다. 검출장치는 중성자 생성 위치로부터 $12.7{\pm}0.02m$ 위치에 설치되었으며 $^{10}B(n,{\alpha}{\gamma})^7Li$ 반응을 이용해 Sm 시료에 입사되는 중성자 선속을 구하였다. 또한 중성자 선속의 변화를 확인하기 위해 $BF_3$ 검출기로 모니터링 하였다. Sm(n,${\gamma}$) 반응단면적 측정결과는 BROND 2.2에 의한 평가결과와 J. C. Chou 및 V. N. Kononov 의 측정값과 비교하였다.

Evaluating the Headspace Volatolome, Primary Metabolites, and Aroma Characteristics of Koji Fermented with Bacillus amyloliquefaciens and Aspergillus oryzae

  • Seo, Han Sol;Lee, Sunmin;Singh, Digar;Park, Min Kyung;Kim, Young-Suk;Shin, Hye Won;Cho, Sun A;Lee, Choong Hwan
    • Journal of Microbiology and Biotechnology
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    • 제28권8호
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    • pp.1260-1269
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    • 2018
  • Production of good Koji primarily depends upon the selection of substrate materials and fermentative microflora, which together influence the characteristic flavor and aroma. Herein, we performed comparative metabolomic analyses of volatile organic compounds (VOCs) and primary metabolites for Koji samples fermented individually with Bacillus amyloliquefaciens and Aspergillus oryzae. The VOCs and primary metabolites were analyzed using headspace solid phase microextraction (HS-SPME) followed by gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). In particular, alcohols, ketones, and furans were mainly detected in Bacillus-fermented Koji (Bacillus Koji, BK), potentially due to the increased levels of lipid oxidation. A cheesy and rancid flavor was characteristic of Bacillus Koji, which is attributable to high content of typical 'off-flavor' compounds. Furthermore, the umami taste engendered by 2-methoxyphenol, (E,E)-2,4-decadienal, and glutamic acid was primarily detected in Bacillus Koji. Alternatively, malty flavor compounds (2-methylpropanal, 2-methylbutanal, 3-methylbutanal) and sweet flavor compounds (monosaccharides and maltol) were relatively abundant in Aspergillus-fermented Koji (Aspergillus Koji, AK). Hence, we argue that the VOC profile of Koji is largely determined by the rational choice of inocula, which modifies the primary metabolomes in Koji substrates, potentially shaping its volatolome as well as the aroma characteristics.

Isolation, Characterization and Whole-Genome Analysis of Paenibacillus andongensis sp.nov. from Korean Soil

  • Yong Guan;Zhun Li;Yoon-Ho Kang;Mi-Kyung Lee
    • Journal of Microbiology and Biotechnology
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    • 제33권6호
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    • pp.753-759
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    • 2023
  • The genus Paenibacillus contains a variety of biologically active compounds that have potential applications in a range of fields, including medicine, agriculture, and livestock, playing an important role in the health and economy of society. Our study focused on the bacterium SS4T (KCTC 43402T = GDMCC 1.3498T), which was characterized using a polyphasic taxonomic approach. This strain was analyzed using antiSMASH, BAGEL4, and PRISM to predict the secondary metabolites. Lassopeptide clusters were found using all three analysis methods, with the possibility of secretion. Additionally, PRISM found three biosynthetic gene clusters (BGC) and predicted the structure of the product. Genome analysis indicated that glucoamylase is present in SS4T. 16S rRNA sequence analysis showed that strain SS4T most closely resembled Paenibacillus marchantiophytorum DSM 29850T (98.22%), Paenibacillus nebraskensis JJ-59T (98.19%), and Paenibacillus aceris KCTC 13870T (98.08%). Analysis of the 16S rRNA gene sequences and Type Strain Genome Server (TYGS) analysis revealed that SS4T belongs to the genus Paenibacillus based on the results of the phylogenetic analysis. As a result of the matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) results, SS4T was determined to belong to the genus Paenibacillus. Comparing P. marchantiophytorum DSM 29850T with average nucleotide identity (ANI 78.97%) and digital DNA-DNA hybridization (dDDH 23%) revealed values that were all less than the threshold for bacterial species differentiation. The results of this study suggest that strain SS4T can be classified as a Paenibacillus andongensis species and is a novel member of the genus Paenibacillus.

Identification of Uncommon Candida Species Using Commercial Identification Systems

  • Kim, Tae-Hyoung;Kweon, Oh Joo;Kim, Hye Ryoun;Lee, Mi-Kyung
    • Journal of Microbiology and Biotechnology
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    • 제26권12호
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    • pp.2206-2213
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    • 2016
  • Recently, several studies have revealed that commercial microbial identification systems do not accurately identify the uncommon causative species of candidiasis, including Candida famata, Meyerozyma guilliermondii, and C. auris. We investigated the accuracy of species-level identification in a collection of clinical isolates previously identified as C. famata (N = 38), C. lusitaniae (N = 1 2), and M. guilliermondii (N = 5) by the Vitek 2 system. All 55 isolates were re-analyzed by the Phoenix system (Becton Dickinson Diagnostics), two matrix-assisted laser desorption ionization-time of flight mass spectrometry analyzers (a Vitek MS and a Bruker Biotyper), and by sequencing of internal transcribed spacer (ITS) regions or 26S rRNA gene D1/D2 domains. Among 38 isolates previously identified as C. famata by the Vitek 2 system, the majority (27/38 isolates, 71.1%) were identified as C. tropicalis (20 isolates) or C. albicans (7 isolates) by ITS sequencing, and none was identified as C. famata. Among 20 isolates that were identified as C. tropicalis, 17 (85%) were isolated from urine. The two isolates that were identified as C. auris by ITS sequencing originated from ear discharge. The Phoenix system did not accurately identify C. lusitaniae, C. krusei, or C. auris. The correct identification rate for 55 isolates was 92.7% (51/55 isolates) for the Vitek MS and 94.6% (52/55 isolates) for the Bruker Biotyper, as compared with results from ITS sequencing. These results suggest that C. famata is very rare in Korea, and that the possibility of misidentification should be noted when an uncommon Candida species is identified.

Proteomic analysis of rice mutants susceptible to Magnaporthe oryzae

  • Ryu, Hak-Seung;Song, Min-Young;Kim, Chi-Yeol;Han, Muho;Lee, Sang-Kyu;Ryoo, Nayeon;Cho, Jung-Il;Hahn, Tae-Ryong;Jeon, Jong-Seong
    • Plant Biotechnology Reports
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    • 제3권2호
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    • pp.167-174
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    • 2009
  • To identify genes involved in rice Pi5-mediated disease resistance to Magnaporthe oryzae, we compared the proteomes of the RIL260 rice strain carrying the Pi5 resistance gene with its susceptible mutants M5465 and M7023. Proteins were extracted from the leaf tissues of both RIL260 and the mutant lines at 0, 24, and 48 h after M. oryzae inoculation and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis identified eight proteins that were differently expressed between the resistant and susceptible plants (three down- and five up-regulated proteins in the mutants). The down-regulated proteins included a triosephosphate isomerase (spot no. 2210), a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (no. 3611), and an unknown protein (no. 4505). In addition, the five up-regulated proteins in the mutants were predicted to be a fructokinase I (no. 313), a glutathione S-transferase (no. 2310), an atpB of chloroplast ATP synthase (no. 3616), an aminopeptidase N (no. 3724), and an unknown protein (no. 308). These results suggest that proteomic analysis of rice susceptible mutants is a useful method for identifying novel proteins involved in resistance to the M. oryzae pathogen.

마이크로비드를 이용한 초소형 C형 간염 검출 시스템의 제작 (Microbead based micro total analysis system for Hepatitis C detection)

  • 심태석;이보람;이상명;김민수;이윤식;김병기;김용권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1629-1630
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    • 2006
  • This paper describes a micro total analysis system ($\mu$ TAS) for detecting and digesting the target protein which includes a bead based temperature controllable microchip and computer based controllers for temperature and valve actuation. We firstly combined the temperature control function with a bead based microchip and realized the on-chip sequential reactions using two kinds of beads. The PEG-grafted bead, on which RNA aptamer was immobilized, was used for capturing and releasing the target protein. The target protein can be chosen by the type of RNA aptamer. In this paper, we used the RNA aptamer of HCV replicase. The trypsin coated bead was used for digesting the released protein prior to the matrix assisted laser desorption ionization time of flight mass spectrometer (MALDI TOF MS). Heat is applied for release of the captured protein binding on the bead, thermal denaturation and trypsin digestion. PDMS microchannel and PDMS micro pneumatic valves were also combined for the small volume liquid handling. The entire procedures for the detection and the digestion of the target protein were successfully carried out on a microchip without any other chemical treatment or off-chip handling using $20\;{\mu}l$ protein mixture within 20 min. We could acquire six matched peaks (7% sequence coverage) of HCV replicase.

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Identification of Novel Target Proteins of Cyclic GMP Signaling Pathways Using Chemical Proteomics

  • Kim, Eui-Kyung;Park, Ji-Man
    • BMB Reports
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    • 제36권3호
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    • pp.299-304
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    • 2003
  • For deciphering the cyclic guanosine monophosphate (cGMP) signaling pathway, we employed chemical proteomics to identify the novel target molecules of cGMP. We used cGMP that was immobilized onto agarose beads with linkers directed at three different positions of cGMP. We performed a pull-down assay using the beads as baits on tissue lysates and identified 9 proteins by MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) mass spectrometry. Some of the identified proteins were previously known cGMP targets, including cGMP-dependent protein kinase and cGMP-stimulated phosphodiesterase. Surprisingly, some of the co-precipitated proteins were never formerly reported to associate with the cGMP signaling pathway. The competition binding assays showed that the interactions are not by nonspecific binding to either the linker or bead itself, but by specific binding to cGMP. Furthermore, we observed that the interactions are highly specific to cGMP against other nucleotides, such as cyclic adenosine monophosphate (cAMP) and 5'-GMP, which are structurally similar to cGMP. As one of the identified targets, MAPK1 was confirmed by immunoblotting with an anti-MAPK1 antibody. For further proof, we observed that the membrane-permeable cGMP (8-bromo cyclic GMP) stimulated mitogen-activated protein kinase 1 signaling in the treated cells. Our present study suggests that chemical proteomics can be a very useful and powerful technique for identifying the target proteins of small bioactive molecules.

Proteomics Analysis of Gastric Epithelial AGS Cells Infected with Epstein-Barr Virus

  • Ding, Yong;Li, Xiao-Rong;Yang, Kai-Yan;Huang, Li-Hua;Hu, Gui;Gao, Kai
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권1호
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    • pp.367-372
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    • 2013
  • Effects of the Epstein-Barr virus (EBV) on cellular protein expression are essential for viral pathogenesis. To characterize the cellular response to EBV infection, differential proteomes of gastric epithelial AGS cells were analyzed with two-dimensional gel electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) and liquid chromatography electrospray/ionization ion trap (LC-ESI-IT) mass spectrometry identification. Mass spectrometry identified 9 altered cellular proteins, including 5 up-regulated and 4 down-regulated proteins after EBV infection. Notably 2-DE analysis revealed that EBV infection induced increased expression of heat shock cognate 71 kDa protein, actin cytoplasmic 1, pyridoxine-5'-phosphate oxidase, caspase 9, and t-complex protein 1 subunit alpha. In addition, EBV infection considerably suppressed those cellular proteins of zinc finger protein 2, cyclin-dependent kinase 2, macrophage-capping protein, and growth/differentiation factor 11. Furthermore, the differential expressional levels of partial proteins (cyclin-dependent kinase 2 and caspase 9) were confirmed by Western blot analysis.Thus, this work effectively provided useful protein-related information to facilitate further investigation of the mechanisms underlying EBV infection and pathogenesis.

Cyclodextrin Glucanotransferase를 이용한 아밀로펙틴 클러스터의 생산 (Enzymatic Production of Amylopectin Cluster Using Cyclodextrin Glucanotransferase)

  • 이혜원;전혜연;최혜정;심재훈
    • 한국식품영양과학회지
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    • 제43권9호
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    • pp.1388-1393
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    • 2014
  • 선행연구에서 얻은 alkalophilic Bacillus I-5 유래의 CGTase wild-type과 가수분해능이 강화된 mutant 효소를 활용하여 waxy rice starch로부터 아밀로펙틴 클러스터를 제조하였다. SEC-MALLS-RI 분석법으로 CGTase wild-type과 mutant 효소가 처리된 시료의 평균 분자량을 확인한 결과 10분가량의 효소반응으로 두 반응 모두 평균 분자량은 $10^4{\sim}10^5Da$으로 급격히 감소하였음을 확인하였으며, 일정 반응 시간이 경과한 이후에는 더 이상 분자량의 감소가 일어나지 않음으로 미루어 시료가 아밀로펙틴 클러스터 단위로 분해되었으며 그 분자량은 $10^4{\sim}10^5Da$ 정도임을 알 수 있다. 또한 MALDI-TOF/MS 분석을 통하여 CGTase wild-type은 다양한 종류의 cyclic 형태의 maltodextrin을 생성하고 있으며 mutant 효소는 주로 소량의 maltooligosaccharide 들을 생산함을 확인하였다.