• Mass Spectrometry Letters
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• v.7 no.4
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• pp.85-90
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• 2016

Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.

• Journal of Navigation and Port Research
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• v.29 no.2
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• pp.119-126
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• 2005

Ferry Golden Jindo collided with Ferry Princess near the No.7 light buoy of Incheon Port No.1 Passage in restricted visibility due to dense fog. The result was that Ferry Golden Jindo got a hole at the starboard midship section shell plating and Ferry Princess sustained damages at the starboard bow and 25 persons injured The aim of this paper is to investigate this collision accident, to clarify its causes, and to prevent such accident from occurring again In short, this collision resulted from Princess' high speed in restricted visibility, Golden Jindo's carelessness of watchkeeping, lack of proper safety training of crew, lack of instruction of supervisor, carelessness af PTMS Center and indifference of Korea Shipping Association, etc.

• Analytical Science and Technology
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• v.20 no.3
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• pp.183-192
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• 2007

The various environmental regulation directives such as RoHS (restriction of hazardous substances in electrical and electronic products) and WEEE (waste from electrical and electronic equipments) are practically used as the technical barrier in international trade (TBT) of vehicles and electrical and electronic products recently. Regarding such an environmental regulation, Korea Research Institute of Standards Science (KRISS) organized a proficiency testing scheme to establish the reliability of measurement results produced by the relevant research institutes and test laboratories in Korea. Participants were 31 laboratories related to production of the electrical and electronic equipments and mobile vehicles. Two polypropylene samples of pellet type were employed as the proficiency testing materials (PTMs). Cadmium and lead were the analytes chosen among six components regulated in European Union (EU) RoHS directive. The PTMs were sent to the participants by post on September $1^{st}$ 2006, and deadline for results submission were October $10^{th}$ 2006. The results of each laboratory were evaluated in comparison with KRISS reference values using Robustic Z-score and Youden plot methods. The results of the various sample digestion methods were also compared. Most of participants reported good agreement within 10 % range of reference values. However, results from several laboratories showed significant biases from reference values. These laboratories should establish the quality assurance system for improvement of the measurement reliability.

• Macromolecular Research
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• v.9 no.4
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• pp.210-219
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• 2001

Quenched and slow cooled as well as isothermally crystallized poly(tetramethylene succinate)(PTMS) films at two different temperatures were prepared. In the process of hydrolysis of the four specimens, structural changes such as the crystallinity, crystal size distribution, lattice parameter, lamellar thickness, long period and surface morphology were investigated by using wide and small angle X-ray scattering (WAXS and SAXS), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The hydrolytic degradation of quenched film was faster than that of slow cooled and isothermally crystallized films. The film crystallized at 100$\^{C}$ exhibited extensive micro voids and thus showed faster degradation than that crystallized at 75$\^{C}$, demonstrating surface morphology is another important factor to govern degradation rate. The crystallinity of the specimen increased by 5-10% and long period decreased after hydrolysis for 20 days. At the initial stage of degradation, the lamellar thickness of quenched film rather increased, while that of slow cooled and isothermally crystallized films decreased. The hydrolytic degradation preferentially occurred in the amorphous region. The hydrolytic degradation in crystal lamellae are mainly at the crystal surfaces.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.54-58
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• 2017

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS) is one of the powerful methods that enable analysis of small molecules as well as large molecules up to about 500,000 Da without severe fragmentation. MALDI-TOF MS, thus, has been a very useful an analytical tool for the confirmation of synthetic molecules, probing PTMs, and identifying structures of a given protein. In recent nuclear medicine, MALDI-TOF MS liner ion mode helps researcher calculate the average number of chelator(or linkage) per an antibody conjugate, such as DOTA-(or DFO-) trastuzumab for labeling a medical radioisotope. This simple technique can be utilized to improve the labeling method and control the quality at the development of antibody-based radiopharmaceuticals, which is very effected to diagnosis and therapy for in vivo tumor cells, with radioisotopes like $^{89}Zr$, $^{64}Cu$, and 177Lu. To minimize the error, MALDI-TOF MS measurement is repeatedly performed for each sample in this study, and external calibration is carried out after data collection.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.277-283
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• 2015

Plant genome analyses, including Arabidopsis thaliana showed a large gene family of plant receptor kinases with various extracellular ligand-binding domain. Now intensively studies to understand physiological and cellular functions for higher plant receptor kinases in diverse and complex biological processes including plant growth, development, ligands perception including steroid hormone and plant-microbe interactions. Brassinosteroids (BRs) as a one of well know steroid hormone are plant growth hormones that control biomass accumulation and also tolerance to many biotic and abiotic stress conditions and hence are of relevance to agriculture. BRI1 receptor kinase, which is localized in plasma membrane in the cell sense BRs and it bind to a receptor protein known as BRASSINOSTEROID INSENSITIVE 1 (BRI1). Recently, we reported that BRI1 and its co-receptor, BRI1-ASSOCIATED KINASE (BAK1) autophosphorylated on tyrosine residue (s) in vitro and in vivo and thus are dual-specificity kinases. Other plant receptor kinases are also phosphorylated on tyrosine residue (s). Post-translational modifications (PTMs) can be studied by altering the residue modified by directed mutagenesis to mimic the modified state or to prevent the modification. These approaches are useful to not only characterize the regulatory role of a given modification, but may also provide opportunities for plant improvement.

• YAKHAK HOEJI
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• v.59 no.3
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• pp.113-119
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• 2015

Protein phosphorylation is one of most important post-translational modifications (PTMs) and plays an important role in regulation of protein function. Here we develop a method for a global identification of phosphopeptides and phosphorylation sites using nano-LC MS/MS. We compared two separation methods, C4 and strong cation ion exchange (SCX). Before phosphopeptides enrichment with $TiO_2$, total proteins from Rat 1 cells have been separated using C4 column or tryptic peptides of proteins from the cells have been separated using SCX column. Finally, we have detected 52 phosphorylation sites on 41 proteins from SCX method and 375 phosphorylation sites on 252 proteins from C4 method, and determined the function and localization of identified phosphoproteins using DAVID software. In particular, we showed new phosphorylation sites from membrane proteins related to various cell signaling mechanisms. This method may contribute to study global signal networks induced by various signals including ligands and drugs.

• 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.

• BMB Reports
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• v.47 no.10
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• pp.593-598
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• 2014

RNA polymerase II carboxyl-terminal domain (RNAPII CTD) phosphatases are responsible for the dephosphorylation of the C-terminal domain of the small subunit of RNAPII in eukaryotes. Recently, we demonstrated the identification of several interacting partners with human small CTD phosphatase1 (hSCP1) and the substrate specificity to delineate an appearance of the dephosphorylation catalyzed by SCP1. In this study, using the established cells for inducibly expressing hSCP1 proteins, we monitored the modification of ${\beta}$-O-linked N-acetylglucosamine (O-GlcNAc). O-GlcNAcylation is one of the most common post-translational modifications (PTMs). To gain insight into the PTM of hSCP1, we used the Western blot, immunoprecipitation, succinylayed wheat germ agglutinin-precipitation, liquid chromatography-mass spectrometry analyses, and site-directed mutagenesis and identified the $Ser^{41}$ residue of hSCP1 as the O-GlcNAc modification site. These results suggest that hSCP1 may be an O-GlcNAcylated protein in vivo, and its N-terminus may function a possible role in the PTM, providing a scaffold for binding the protein(s).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.40-43
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• 2016

Transparent color coating films were fabricated on a glass substrate by using sol-gel hybrid binder and organic dye. Sol-gel hybrid binder coating film fabricated with PTMS of 0.03 mole showed a very high pencil hardness of 9 H. As the withdrawal speed increased from 1.0 mm/s to 5.0 mm/sec, The yellowness ($b^*$) of coating glass also gradually increased. The transmittance of yellow color coating glass was 82.6% and the haze of coating glass was 0.35%. Red and blue color coating glasses also showed the high transmittance of 62.4% and 80.6% respectively. The surface hardness of color coating films was 6 H.