• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.94.2-94.2
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• 2007

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• Mass Spectrometry Letters
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• v.5 no.4
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• pp.110-114
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• 2014

The method of direct mass spectrometry profiling is reliable and reproducible for the rapid identification of clinical isolates of bacteria and fungi. This is the first study evaluating the approach of MALDI-TOF mass spectrometry profiling for rapid identification of carbapenemase-resistant enterobacteriaceae (CRE). Proof of concept was achieved by the discrimination of CRE using MALDI Biotyper MS based on the protein. This profiling appears promising by the visual observation of consistent unique peaks, albeit low intensity, that could be picked up from the mean spectra (MSP) method. The Biotyper MSP creation and identification methods needed to be optimized to provide significantly improved differences in scores to allow for subspecies identification with and without carbapenemases. These spectra were subjected to visual peak picking and in all cases; there were pertinent differences in the presence or absence of potential biomarker peaks to differentiate isolates. We also evaluated this method for potential discrimination between different carbapenemases bacteria, utilizing the same strategy. Based on our data and pending further investigation in other CREs, MALDI-TOF MS has potential as a diagnostic tool for the rapid identification of even closely related carbapenemases but would require a paradigm shift in which Biotyper suppliers enable more flexible software control of mass spectral profiling methods.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.620-627
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• 2004

On the foundation of a database of genome sequences and protein analyses, the ability to clone a gene based on a peptide analysis is becoming more feasible and effective for identifying a specific gene and its protein product of interest. As such, the current study conducted a protein analysis using 2-D PAGE followed by MALDI- TOF and ESI-MS to identify a highly expressed gene product of C. parasitica. A distinctive and highly expressed protein spot with a molecular size of 47.2 kDa was randomly selected and MALDI-TOF MS analysis was conducted. A homology search indicated that the protein appeared to be a fungal enolase (enol). Meanwhile, multiple alignments of fungal enolases revealed a conserved amino acid sequence, from which degenerated primers were designed. A screening of the genomic $\lambda$ library of C. parasitica, using the PCR amplicon as a probe, was conducted to obtain the full-length gene, while RT-PCR was performed for the cDNA. The E. coli-expressed eno 1 exhibited enolase enzymatic activity, indicating that the cloned gene encoded the C. parasitica enolase. Moreover, ESI-MS of two of the separated peptides resolved from the protein spot on 2-D PAGE revealed sequences identical to the deduced sequences, suggesting that the cloned gene indeed encoded the resolved protein spot. Northern blot analysis indicated a consistent accumulation of an eno1 transcript during the cultivation.

• Biomedical Science Letters
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• v.23 no.4
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• pp.395-401
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• 2017

Various preclinical and clinical trials have been conducted the efficacy of celastrol. In data presented in the current manuscript is the first trial to inhibit Helicobacter pylori with celastrol. In this study, the quantitative change of various H. pylori proteins including CagA and VacA by the anti-bacterial effect of celastrol was determined. The anti-H. pylori effects of celastrol was investigated by performing 2-dimensional electrophoresis and additional supporting experiments. After 2-dimensional electrophoresis analysis, spot intensities were analyzed and then each spot was identified using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) or peptide sequencing using Finnigan LCQ ion trap mass spectrometer (LC-MS/MS). The results show that celastrol has multiple effects on protein expression in H. pylori.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.315-319
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• 2002

Visible surface-assisted desorption/ionization mass spectrometry (SALDI-MS) has been investigated for several small macromolecules deposited on the graphite plate using laser radiation at 532 nm where most of the macromolecules are transparent. The graphite surface functioned well as a photon absorbing material and an energy transfer mediator for visible light. The results show that visible SALDI is a much softer ionization technique than UV-MALDI and FAB-MS in our results with synthetic macromolecules, PPG, PPGMBE and cavitand molecules. For the SALDI of biomolecules, glycerol as a proton source was essential with the graphite plate. As in visible SALDI, the role division of the photon absorbing material and the cationization agent can provide a generality in mass spectrometric analysis of macromolecules compared with MALDI using the dual functional matrix.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1183-1186
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• 2011

The unique Br signature was utilized for C-terminal amino acid sequencing of model peptides. C-terminal carboxyl group was selectively derivatized in peptides, containing side chain carboxyl group, using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) and Br was introduced using 4-bromophenylhydrazine hydrochloride (BPH) in a one pot reaction. Matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) tandem mass spectra were obtained carrying the Br signature in the y-series ions. The Br signature facilitated C-terminal sequencing and discrimination of C-terminal carboxyl groups in the free acid and amide forms.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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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.

• Mass Spectrometry Letters
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• v.11 no.1
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• pp.6-9
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• 2020

Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of ionic liquid matrices (ILMs) prepared using pyridine and dihydroxybenzoic acid (DHB), such as 2,3-DHB and 2,5-DHB, displayed an unconventional peak at m/z 232.0, which was regarded as [DHB+pyridine-H]⁺. The peak at m/z 232.0 was not observed from other ILMs prepared using other DHB isomers, such as 2,4-DHB, 2,6-DHB, 3,4-DHB, and 3,5-DHB. Two requirements to observe the peak at m/z 232.0 in a DHB/pyridine ILM are suggested. First, carboxyl and hydroxyl groups must be located ortho to each other. Second, the secondary hydroxyl group must be located at a carbon with a high electron density. Based on these two requirements, a potential mechanism for the generation of the peak at m/z 232.0 is suggested.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1127-1130
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• 2009

The effects of different dihydroxybenzoic acid (DHB) isomers, when used as matrix materials in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), were investigated in analyses of polyethylene glycol (PEG) polymers. PEG polymers ranging from 400 to 8,000 Da were prepared in different DHB isomer matrices using solvent-based and solvent-free methods. PEG samples were detected only in matrices of 2,3-DHB, 2,5-DHB, and 2,6-DHB while the most intense peaks were observed using 2,6-DHB in both solvent-free and solvent-based preparations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.3
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• pp.1-21
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• 1999

화장품, 의료용, 가정용품 및 공업용제품에까지 광범위한 용도로 사용량이 많은 중요한 비이온 계면활성제의 종류 중에서 polyoxyethylene(POE) 부가형 계면활성제의 경우 그 부가몰수에 따라 특성이 달라지고 용도가 다르게 사용된다. 이때 부가된 분자들의 분자량이 크고 분포를 이루는 혼합물이기 때문에 분석이 매우 어렵다. 따라서 MALDI-TOF/MS 방법을 이용하여 이들의 분자량과 그 분포를 측정함으로써 쉽고 빠르게 측정할 수 있는 새로운 방법을 개발하고자 하였다. 이 논문에서는 화장품에 주로 사용되는 비이온 계면활성제를 선택하여 MALDI-TOF/AfS를 측정하여 스펙트럼으로부터 분자량 분포와 POE부가정도를 측정할 수 있었다. 그리고 이 조건을 적용하여 시중에 판매되는 제품에서 추출된 비이온 계면활성제의 MALDI-TOF/MS 스펙트럼으로부터 분자량 분포와 POE 부가 정도를 확인 할 수 있었다.