• BMB Reports
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• v.38 no.3
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• pp.307-313
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• 2005

Thiobacillus ferrooxidans is one of the most important bacterium used in bioleaching, and can utilize $Fe^{2+}$ or sulphide as energy source. Growth curves for Thiobacillus ferrooxidans have been tested, which show lag, logarithmic, stationary and aging phases as seen in other bacteria. The logarithmic phases were from 10 to 32 hours for Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ and from 4 to 12 days for Thiobacillus ferrooxidans cultivated with elemental sulphur. Differences of protein patterns of Thiobacillus ferrooxidans growing on elemental sulphur and $Fe^{2+}$ separately were investigated after cultivation at $30^{\circ}C$ by the analysis of two-dimensional gel electrophoresis (2-DE), matrix-assisted laser desorption/ ionization (MALDI)-Mass spectrometry and ESI-MS/MS. From the 7 identified protein spots, 11 spots were found more abundant when growing on elemental sulphur. By contrast 6 protein spots were found decreased at elemental cultivation condition. Among the proteins identified, cytochrome C have been previously identified as necessary elements of electron-transfering pathway for Thiobacillus ferrooxidans to oxidize $Fe^{2+}$; ATP synthase alpha chain and beta are expressed increased when Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ as energy source. ATP synthase Beta chain is the catalytic subunit, and ATP synthase alpha chain is a regulatory subunit. The function of ATPase produces ATP from ADP in the presence of a proton gradient across the membrane.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.77-81
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• 2020

Characterization of the various chemical aspects of composite polymers is important for quality control of manufactured polymers. In this study, we compared three suitable matrices (α cyano-4-hydroxycinnamic acid [CHCA], 2,5 dihydroxy benzoic acid [2,5-DHB], and dithranol), to characterize various synthetic polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Although the spectra obtained with the CHCA and 2,5-DHB matrices were generally good, in certain samples ghost peaks disappeared only when dithranol was used as the matrix. Furthermore, we examined the use of sodium trifluoroacetate (NaTFA) as an additive to reduce interference by metals and copolymers in the spectra. In conclusion, appropriate selection of a matrix, according to the characteristics of the polymer, and the use of additives to improve sensitivity are important considerations for polymer analysis and development.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.4
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• pp.207-211
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• 2004

The purpose of the present study was to evaluate the expression of cardiac marker protein in rabbit cardiac tissue that was exposed to ischemic preconditioning (IPC), or ischemiareperfusion injury (IR) using two-dimensional gel electrophoresis (2DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). We compared 2DE gels of control (uninjured) cardiac tissue with those of IPC and IR cardiac tissue. Expression of one protein was detected in IR heart tissue, however the protein was not detected in the samples of control and IPC tissue. To further characterize the detected protein molecule, the protein in the 2D gel was isolated and subjected to trypsin digestion, followed by MALDI-MS. The protein was identified as myoglobin, which was confirmed also by Western blot analysis. These results are consistent with previous studies of cardiac markers in ischemic hearts, indicating myoglobin as a suitable marker of myocardial injury. In addition, the present use of multiple techniques indicates that proteomic analysis is an appropriate means to identify cardiac markers in studies of IPC and IR.

• Journal of Life Science
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• v.18 no.6
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• pp.814-825
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• 2008

Ascochlorin (ASC) is prenyl-phenol compound that was isolated from the fungus Ascochyta viciae. ASC reduces serum cholesterol and triglyceride levels, and suppresses hypertension, tumor development, ameliorates type I and II diabetes. Here, to better understand the mechanisms by which ASC regulates physiological or pathological events and induces responses in the pharmacological treatment of inflammation, we performed differential analysis of the proteome of the mouse macrophage RAW264.7 cells in response to ASC. In this study, we used a proteomic analysis of LPS-induced RAW264.7 cells treated by ASC, to identify proteins potentially involved in inflammatory processes. The RAW264.7 cell proteomes with and without treatment with ASC were compared using two-dimensional electrophoresis (2-D SDS-PAGE), matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS) and bioinformatics. The largest differences in expression were observed for the calreticulin (4-fold decrease), ${\beta}-actin$ (4-fold decrease) and vimentin (1.5-fold decrease). In addition, rabaptin was increased 3-fold in RAW264.7 cells treated with ASC. The expression of some selected proteins was confirmed by RT-PCR analysis.

• Mass Spectrometry Letters
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• v.10 no.3
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• pp.84-87
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• 2019

Liquid chromatography mass spectrometry is widely employed in proteomics studies. One of such instruments is the Liquid Chromatography (LC)-Matrix-assisted laser desorption ionisation (MALDI)-Time of flight (TOF) or LC-MALDI-TOF/TOF. In this study, this instrument was used to identify the membrane proteins of a protozoan parasite namely Entamoeba histolytica. It causes amoebiasis in human. The E. histolytica trophozoites were cultured prior to the membrane protein extraction using the conventional method, $ProteoPrep^{(R)}$ and $ProteoExtract^{(R)}$ kits. Then, the membrane protein extracts were trypticdigested and analysed by LC-MALDI-TOF/TOF. Approximately, 194 proteins were identified and 27.8% (54) were predicted as membrane proteins having 1 to 15 transmembrane regions and signal peptides by combining all three extraction methods. Also, this study has discovered 3 unique proteins as compared to our previous study which merit further investigation.

• Mass Spectrometry Letters
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• v.2 no.3
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• pp.61-64
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• 2011

Matrix Assisted Laser Desorption/Ionization-Time-of-Flight mass spectrometry (MALDI-TOF-MS) is the most widely used MS technique for glycan analysis. However, the poor point-to-point and sample-to-sample reproducibility becomes a limit in glycan biomarker research. A prespotted MALDI plate which overcomes the large crystal formation of 2,5-dihydroxybenzoic acid (DHB) has been developed and applied for glycan analysis. A homogeneous matrix coated surface without a crystal structure was formed on a hydrophilic/ hydrophobic patterned surface using a piezoelectric device. The reproducible MALDI-TOF-MS data have been presented using MALDI imaging of beer glycan as well as serum glycan eluted from 10% and 20% ACN elution fractions. The glycan profile from the serum glycan by MALDI-TOF-MS with a DHB prespotted plate was highly conserved for 10 different spectra and the coefficient of variations of significant ion peaks of MALDI data varies from 3.59 to 19.95.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.915-920
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• 2011

Four esters of succinic and maleic acid were synthesized, separated by thin-layer chromatography (TLC), and identified using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). A comparison of matrix materials showed that 2,6-dihydroxybenzoic acid (2,6-DHB) yielded a greater ionization efficiency than 2,5-DHB prior to TLC separation. The location of each ester sample on the TLC plate was estimated by comparing the developed plate with a duplicate plate that had been visualized by immersion in a $KMnO_4$ solution. Generally, mass spectra obtained from the $KMnO_4$-visualized plate were relatively poor. Reproducible mass spectra with high peak abundance were difficult to obtain using the 2,6-DHB matrix from crude synthetic esters extracted from the TLC plates. Significant improvements in both reproducibility and sensitivity were realized by using pencil lead as the MALDI matrix. The current methodology will be beneficial to organic chemists since it can provide a guideline for simple and rapid characterization of small organic compounds.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.275-283
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• 2018

Helicobacter pylori is a causative organism of various gastrointestinal diseases, including chronic gastritis, gastric ulcer, or gastric adenocarcinoma. Pathogenic factors, such as cytotoxin-associated protein A (CagA) and vacuolating cytotoxic protein A (VacA), play a role. This study analyzed qualitatively and quantitatively the effects of zerumbone on the changes in the protein expression levels of various H. pylori proteins, including CagA and VacA. Approximately 200 significant proteins were screened for the H. pylori 60190 (VacA positive / CagA positive; Eastern type) strain, and proteomic analysis was performed on 13 protein molecules that were clinically significant. After two-dimensional electrophoresis (2-DE), $ImageMaster^{TM}$ 2-DE Platinum software was used for quantitative measurements of protein spots. Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-TOF-MS) and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) were used for protein identification. After intensive analysis of the proteins that showed significant changes, a reverse transcription-polymerase chain reaction was performed as required to verify the results. In this study, the significance of zerumbone as a therapeutic agent for H. pylori infection was examined by screening a new pharmacological activity mechanism of zerumbone.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.81-84
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• 2021

Collagen, which accounts for one-third of human protein, is reduced due to human aging, and much attention is focused on making collagen into food to prevent such aging. Gel permeation chromatography with Reflective Index (RI) detection (GPC/RI) was chosen as the most suitable instrument to confirm molecular weight distribution, and we explored the use of this technique for analysis of collagen peptide molecular sizes and distributions. Data reliability was verified by matrix-assisted laser desorption/ionization coupled to time-of-flight (MALDI-TOF) mass spectrometric analysis. The data were considered meaningful for comparative analysis of molecular weight distribution patterns.

• Biomedical Science Letters
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• v.28 no.3
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• pp.145-156
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• 2022

Over the past few decades, few technologies have had a greater impact on clinical microbiology laboratories than matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS). The MALDI-TOF MS is a fast, accurate, and low-cost and efficient method of microbial identification. This technology generates characteristic mass spectral fingerprints that is a unique signature for each microorganism, making it an ideal method for accurate identification at the genus and species levels of both bacterial and fastidious microorganism such as anaerobes, mycobacterium and fungi etc. In addition, MALDI-TOF MS has been successfully used in microbial subtyping and susceptibility tests such as determination of resistance genes. In this study, the authors summarized the application of MALDI-TOF MS in clinical microbiology and clinical research and explored the future of MALDI-TOF MS.