• BMB Reports
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• v.45 no.6
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• pp.323-330
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• 2012

The glycome consists of all glycans (or carbohydrates) within a biological system, and modulates a wide range of important biological activities, from protein folding to cellular communications. The mining of the glycome for disease markers represents a new paradigm for biomarker discovery; however, this effort is severely complicated by the vast complexity and structural diversity of glycans. This review summarizes recent developments in analytical technology and methodology as applied to the fields of glycomics and glycoproteomics. Mass spectrometric strategies for glycan compositional profiling are described, as are potential refinements which allow structure-specific profiling. Analytical methods that can discern protein glycosylation at a specific site of modification are also discussed in detail. Biomarker discovery applications are shown at each level of analysis, highlighting the key role that glycoscience can play in helping scientists understand disease biology.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.985-987
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• 2008

Parathion is an organophosphate pesticide being legally applied for the purpose of agriculture and is being manufactured in Korea. A gas chromatography/mass spectrometric method was developed for the determination of parathion urinary metabolite, p-nitrophenol. p-Nitrophenol was extracted from weak acidic urine, and then measured by gas chromatography-mass spectrometry (selected ion monitoring). The recovery of pnitrophenol in the overall procedure was 88.2%. The detection limit of the assay was 1.0 $\mu$ g/L based upon assayed urine of 2.0 mL. The method was applied to the determination of p-nitrophenol in urine of workers of a parathion industry. Spot urines of workers of a parathion industry were sampled at the end of shift and pnitrophenol was analyzed using above developed method. p-Nitrophenol could be detected in all of the urine samples at concentrations varying from 3.0 to 681 $\mu$ g/L.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.923-931
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• 2013

Rapamycin, known as an inhibitor of Target of Rapamycin (TOR), is an immunosuppressant drug used to prevent rejection in organ transplantation. Despite the close association of the TOR signaling cascade with various scopes of metabolism, it has not yet been thoroughly investigated at the metabolome level. In our current study, we applied mass spectrometric analysis for profiling primary metabolism in order to capture the responsive dynamics of the Chlamydomonas metabolome to the inhibition of TOR by rapamycin. Accordingly, we identified the impact of the rapamycin treatment at the level of metabolomic phenotypes that were clearly distinguished by multivariate statistical analysis. Pathway analysis pinpointed that inactivation of the TCA cycle was accompanied by the inhibition of cellular growth. Relative to the constant suppression of the TCA cycle, most amino acids were significantly increased in a time-dependent manner by longer exposure to rapamycin treatment, after an initial down-regulation at the early stage of exposure. Finally, we explored the isolation of the responsive metabolic factors into the rapamycin treatment and the culture duration, respectively.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.806-808
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• 2004

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of icing inhibitors, ethylene glycol monomethyl ether and diethylene glycol monomethyl ether in ground water contaminated with JP-8. Ethylene glycol monobutyl ether and ethylene glycol monoethyl ether were used as the internal standard and surrogate, respectively. 100 mL of ground water was extracted twice with 20 mL of methylene chloride. The extract was concentrated to dryness, dissolved with 100 ${\mu}$L of methanol and analyzed by GC-MS (SIM). The use of an Innowax column gave the peaks good chromatographic properties, and the extraction of these compounds from samples gave recoveries of about 50% with small variations. The method detection limits of the target compounds were in a range of 0.5-0.8 ng/mL in ground water.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1036-1039
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• 1996

Synthetic lipoidal peptides based on viral protein sequences have been prepared. These peptides contain an N-palmitoyl group at the N-terminal residue, which is a modified cysteine, containing a S-[2,3-bis(acyloxy)-(2-R,S)-propyl] moiety. When this residue (Pam3Cys) is at the N-terminus of a synthetic peptide, it acts as potent immunoadjuvant to enhance both IgM and IgG antibody responses to the attached peptide. Conventional analytical procedures (e.g., Edman degradation and amino acid analysis) are either not applicable due to the N-terminal modification, or do not provide confirmation of the intact structure. Chromatographic analysis is also hindered by the tendency of these lipoidal Pam3Cys peptides to form large aggregates, and in some cases to be permanently adsorbed on reversed phase columns. We have applied several mass spectrometric techniques, including fast atom bombardment (FAB), electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) to characterize the intact structures of a number of different Pam3Cys synthetic peptides. The MALDI-MS has been found to be the most sensitive for the analysis of the structure of Pam3Cys peptides.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.194-196
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• 1998

The metabolism of dromostanolone (2α-methyl-5α- androstan-17β-ol-3-one) was studied in three adult volunteers after oral dose of 20 mg. Solvent extracts of urine obtained after enzyme hydrolysis were derivatized with MSTFA/TMCS and MSTFA/TMIS. The structures of intact drug and its metabolites were determined by gas chromatography/mass spectrometry (GC/MS) in electron impact (EI) mode. The major metabolite (2α-methyl-5α- androstan-3α-ol-17-one), its 3β-epimer, parent compound, and several hydroxylated metabolites including intact drug were detected by comparing total ion chromatograms of control urine with that of the administered sample. Two epimers of 2α-methyl-5α- androstan-3,17β-diol were detected using selected ion monitoring. The maximum excretion of dromostanolone and 2α-methyl-5α- androstan-3α-ol-17-one was reached in 6.2-15 hr. The half-life of intact dromostanolone was 5.3 hr. About 3.0% of the administered amount was found to be excreted within 95 hr as unchanged form.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.224.1-224.1
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• 2003

A sensitive and selective liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the determination of beraprost in human plasma. Plasma samples were transferred into 96-well OASIS HLB extraction plate using an automated sample handling system and the drugs were eluted with methanol. The eluents were then evaporated and reconstituted with water. All sample transfer and solid-phase extraction (SPE) was automated through the application of both the PerkinElmer MultiPROBE II HT and TOMTEC Quadra 96 workstation. (omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.105.1-105.1
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• 2016

Many of the complex materials developed today derive their unique properties from the presence of multiple phases or from local variations in elemental concentration. Simply performing analysis of the bulk materials is not sufficient to achieve a true understanding of their physical and chemical natures. Secondary ion mass spectrometer (SIMS) has met with a great deal of success in material characterization. The basis of SIMS is the use of a focused ion beam to erode sample atoms from the selected region. The atoms undergo a charge exchange with their local environment, resulting in their conversion to positive and negative secondary ions. The mass spectrometric analysis of these secondary ions is a robust method capable of identifying elemental distribution from hydrogen to uranium with detectability of the parts per million (ppm) or parts per billion (ppb) in atomic range. Nano secondary ion mass spectrometer (Nano SIMS, Cameca Nano-SIMS 50) equipped with the reactive ion such as a cesium gun and duoplasmatron gun has a spatial resolution of 50 nm which is much smaller than other SIMS. Therefore, Nano SIMS is a very valuable tool to map the spatial distribution of elements on the surface of various materials In this talk, the surface imaging applications of Nano SIMS in KBSI will be presented.

• Mass Spectrometry Letters
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• v.6 no.1
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• pp.7-12
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• 2015

In the present study, we proposed a simple ESI-MS model for determining $Zn^{2+}$ binding (or dissociation) constants for zinc finger peptides (ZFPs) with a unique ${\beta}{\beta}{\alpha}$ fold consensus. The ionization efficiency (response) factors for this model, i.e., ${\alpha}$ and ${\beta}$, could be determined for ZiCo ZFP with a known $Zn^{2+}$ binding constant. We could determine the binding constants for other ZFPs assuming those with a ${\beta}{\beta}{\alpha}$ consensus conformation have the same ${\alpha}/{\beta}$ response ratio. In general, the ZPF dissociation constants exhibited $K_d$ values of $10^{-7}{\sim}10^{-9}M$, while $K_d$ values for a negative control non-specific $Zn^{2+}$ peptides were high, e.g., $5.5{\times}10^{-6}M$ and $4.3{\times}10^{-4}M$ for BBA1 and melittin, respectively.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.845-850
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• 2014

The rapid development of shotgun proteomics is paving the way for extensive proteome profiling, while providing extensive information on various post translational modifications (PTMs) that occur to a proteome of interest. For example, the current phosphoproteomic methods can yield more than 10,000 phosphopeptides identified from a proteome sample. Despite these developments, it remains a challenging issue to pinpoint the true phosphorylation sites, especially when multiple sites are possible for phosphorylation in the peptides. We developed the Phospho-UMC filter, which is a simple method of localizing the site of phosphorylation using unique mass classes (UMCs) information to differentiate phosphopeptides with different phosphorylation sites and increase the confidence in phosphorylation site localization. The method was applied to large scale phosphopeptide profiling data and was demonstrated to be effective in the reducing ambiguity associated with the tandem mass spectrometric data analysis of phosphopeptides.