• Molecules and Cells
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• v.37 no.5
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• pp.399-405
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• 2014

Autophagy targets cytoplasmic cargo to a lytic compartment for degradation. Autophagy-related (Atg) proteins, including the transmembrane protein Atg9, are involved in different steps of autophagy in yeast and mammalian cells. Functional classification of core Atg proteins in plants has not been clearly confirmed, partly because of the limited availability of reliable assays for monitoring autophagic flux. By using proUBQ10-GFP-ATG8a as an autophagic marker, we showed that autophagic flux is reduced but not completely compromised in Arabidopsis thaliana atg9 mutants. In contrast, we confirmed full inhibition of auto-phagic flux in atg7 and that the difference in autophagy was consistent with the differences in mutant phenotypes such as hypersensitivity to nutrient stress and selective autophagy. Autophagic flux is also reduced by an inhibitor of phosphatidylinositol kinase. Our data indicated that atg9 is phenotypically distinct from atg7 and atg2 in Arabidopsis, and we proposed that ATG9 and phosphatidylinositol kinase activity contribute to efficient autophagy in Arabidopsis.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.3
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• pp.85-90
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• 2001

The determination of DNA hybridization reaction can apply the molecular biology research, clinic diagnostics, bioengineering, environment monitoring, food science and other application area. So, the improvement of DNA detection system is very important for the determination of this hybridization reaction. In this study, we report the characterization of the probe and target oligonucleotide hybridization reaction using the evanescent field microscopy. First, we have fabricated DNA chip microarray. The particles which were immobilized oligonucleotides were arranged by the random fluidic self-assembly on the pattern chips, using hydrophobic interaction. Second, we have detected DNA hybridization reaction using evanescent field microscopy. The 5'-biotinylated probe oligonucleotides were immobilized on the surface of DNA chip microarray and the hybridization reaction with the Rhodamine conjugated target oligonucleotide was excited fluorescence generated on the evanescent field microscopy. In the foundation of this result, we could be employed as the basis of a probe olidonucleotide, capable of detecting the target oligonucleotide and monitoring it in a large analyte concentration range and various mismatching condition.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.85-92
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• 2021

The therapeutic antibody drug market has experienced explosive growth as mAbs become the main therapeutic modality for a variety of diseases. Characterization of glycosylation that directly affects the efficacy and safety of therapeutic monoclonal antibodies (mAbs) is critical for therapeutics development, bioprocess system optimization, lot release, and comparability evaluation. The LC/MS approach has been widely used to structurally characterize mAbs, and recently attempts have been made to obtain comprehensive information on the primary structure and post-translational modifications (PTMs) of mAbs through intact protein analysis. In this study, we performed state-of-the-art LC/MS based intact protein analysis to readily identify and characterize glycoforms of various mAbs. Different glycoforms of mAbs produced in different expression cell lines including CHO, SP2/0 and HEK cells were monitored and compared. In addition, the comparability of protein molecular weight, glycoform pattern, and relative abundances of glycoforms between the commercialized trastuzumab biosimilar and the original product was determined in detail using the given platform. Intact mAb analysis allowed us to gain insight into the overall mAb structure, including the complexity and diversity of glycosylation. Furthermore, our analytical platform with high reproducibility is expected to be widely used for biopharmaceutical characterization required at all stages of drug development and manufacturing.

• Journal of the Korean institute of surface engineering
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• v.57 no.2
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• pp.71-85
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• 2024

This article provides an overview of Raman spectroscopy and its practical applications for surface analysis of semiconductor processes including real-time monitoring. Raman spectroscopy is a technique that uses the inelastic scattering of light to provide information on molecular structure and vibrations. Since its inception in 1928, Raman spectroscopy has undergone continuous development, and with the advent of SERS(Surface Enhanced Raman Spectroscopy), TERS(Tip Enhanced Raman Spectroscopy), and confocal Raman spectroscopy, it has proven to be highly advantageous in nano-scale analysis due to its high resolution, high sensitivity, and non-destructive nature. In the field of semiconductor processing, Raman spectroscopy is particularly useful for substrate stress and interface characterization, quality analysis of thin films, elucidation of etching process mechanisms, and detection of residues.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.3
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• pp.160-180
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• 2012

We have studied the eukaryotic plankton species diversity to compare the community structure of fresh and brackish waters in the lower reaches of the Nakdong River using metagenomic methods. We constructed 18S rDNA clone libraries of total DNAs extracted from environmental water samples collected at Mulgeum (MG100929, fresh) and Eulsukdo bridge (ES, brackish). Through the steps of colony PCR, PCR-RFLP, sequencing and similarity analysis, we discovered the diverse species composition of eukaryotic plankton. Total 338 clones (170 at MG100929 and 168 at ES) were analyzed, and then we found 74 phylotypes (49 for MG100929 and 25 for ES). From the phylogenetic analysis, we confirmed various eukaryotic plankton of broad range of taxonomic groups, including Stramenopiles, Cryptophyta, Viridiplantae, Alveolata, Rhizaria, Metazoa, and Fungi. We also found several unreported species in Korea and candidates of new taxonomic entities at levels higher than genus. Especially, the cryptic species diversity including unreported phylotypes of Pirsonia (Stramenopiles) and Perkinsea (Alveolata) suggests that the molecular monitoring method can produce new informative biological data in monitoring the changes in the Nakdong River Mouth ecosystem.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.17-21
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• 2023

In this study, we evaluated the targeting of prostate cancer (PCa) using [¹⁸F]Florastamin in non-clinical study, for the purpose of therapeutic monitoring of [¹⁷⁷Lu]Ludotadipep, a therapeutic radiopharmaceutical for PCa, [¹⁸F]Florastamin/[¹⁷⁷Lu]Ludotadipep was co-administered to a single-individual prostate tumor bearing mouse model, mimicking clinical condition. Considering the difference in half-life of the two isotopes (¹⁸F or ¹⁷⁷Lu), image scan of whole-body autoradiography was performed at 24 or 48 h after preparation of frozen section, respectively. Then, it was confirmed whether they showed the same targeting efficiency for the area of tumor. A tumor xenograft model was prepared using PSMA-overexpressing PC3-PIP prostate cancer cells. [¹⁸F]Florastamin [111 MBq (3 mCi) in 100 µL]/¹⁷⁷Lu]Ludotadipep [3.7 MBq (100 µCi) in 100 µL] was co-administered through the tail vein, and 2 hours after administration, the mice were frozen, and after freezing for 24 hours, whole-body cryosection was performed at 24 h after freezing. Image scanning using cryosection was performed after 24 or 48 hours after freezing, respectively. In the scan image after 24 hours, tumor uptake of [¹⁸F] Florastamin/[¹⁷⁷Lu]Ludotadipep were simultaneously observed specific uptake in the tumor. In the scan image after 48 hours in the same section, signal of ¹⁸F was lost by decay of radioisotope, and specific uptake image for [¹⁷⁷Lu]Ludotadipep was observed in the tumor. Uptake of [¹⁷⁷Lu]Ludotadipep was specific to the same tumor region where [¹⁸F]Florastamin/[¹⁷⁷Lu]Ludotadipep was uptake. These results suggested that [¹⁸F]Florastamin showed the same tumor uptake efficiency to PCa as [¹⁷⁷Lu]Ludotadipep, and effective therapeutic monitoring is expected to be enable using [¹⁸F]Florastamin during [¹⁷⁷Lu]Ludotadipep therapy for PCa.

• Journal of Microbiology
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• v.42 no.4
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• pp.361-364
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• 2004

Internal ribosome entry site (IRES) of the hepatitis C virus (HCV) is known to be essential for HCV replication and most conserved among HCV variants. Hence, IRES RNA is a good therapeutic target for RNA-based inhibitors, such as ribozymes. We previously proposed a new anti-HCV modulation strategy based on trans-splicing ribozymes, which can selectively replace HCV transcripts with a new RNA that exerts anti-HCV activity. To explore this procedure, sites which are accessible to ribozymes in HCV IRES were previously determined by employing an RNA mapping method in vitro. In this study, we evaluate the intracellular accessibility of the ribozymes by comparing the trans-splicing activ­ities in cells of several ribozymes targeting different sites of the HCV IRES RNA. We assessed the intra­cellular activities of the ribozymes by monitoring their target-specific induction degree of both reporter gene activity and cytotoxin expression. The ribozyme capable of targeting the most accessible site iden­tified by the mapping studies then harbored the most active trans-splicing activity in cells. These results suggest that the target sites predicted to be accessible are truly the most accessible in the cells, and thus, could be applied to the development of various RNA-based anti-HCV therapies.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.184-188
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• 2002

Unsaturated $Cr(CO)_x(1{\leq}x{\leq}5)$molecules were generated in the gas phase from photolysis of $Cr(CO)_6$vapor in He using an unfocussed weak UV laser pulse and their reactions with $O_2$ and $N_2O$ have been studied. The formation and disappearance of the ground state CrO molecules were identified by monitoring laser-induced fluorescence(LIF) intensities vs delay time between the photolysis and probe pulses. The photolysis laser power dependence as well as the delay time dependence of LIF intensities from the CrO orange system showed different behavior as those from ground state Cr atoms, suggesting that the ground state CrO molecules were generated from the reaction between $O_2/N_2O$ and photo-fragments of $Cr(CO)_6$ by one photon absorption. The depletion rate constants for the ground state CrO by $O_2$ and $N_2O$ are $5.4{\pm}0.2{\times}10^{-11}$ and $6.5{\pm}0.4{\times}10^{-12}cm^3molecule^{-1}s^{-1}$, respectively.

• Journal of Photoscience
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• v.10 no.2
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• pp.189-193
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• 2003

The effects of light on the regulation of ethylene biosynthesis during development of mung bean seedlings were investigated by monitoring the differential expression of seven 1-aminocyclopropane-l-carboxylate (ACC) synthase and two ACC oxidase genes. Among them, only the expression of VR-ACS1, VR-ACS6, VR-ACS7, VR-ACO1 and VR-AC02 was observable in etiolated mung bean hypocotyls. When the seedlings were de-etiolated for 1 d under a light/dark cycle of 16 h/8 h, the expression of VR-ACS6, VR-ACS7 and VR-ACO2 was controlled negatively by light. The expression of VR-ACS1 showed a tendency to increase until 6 h after a dark-to-light transition and then decreased at 12 h. On the other hand, the expression of VR-ACO1 was mostly constitutive up to 12 h after the dark-to-light transition. The opening of hypocotyl hooks during de-etiolation in the light was stimulated by the inhibition of the action of endogenous ethylene in the presence of 1-MCP. These results suggest that the negative regulation of light on the expression of ACC synthase and ACC oxidase genes eventually results in the inhibition of ethylene production with an acceleration of the opening of apical hooks.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1221-1227
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• 2011

Ethyl pyruvate (EP) is known as a scavenger of reactive oxygen species (ROS) in the body through its role in the donation of diketone groups to metals to form an EP-metal complex. In order to develop a method for the quantification of EP in biological media, a sensitive and specific, high-performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI/MS) method is used to determine the EP-alkali metal ion binding species. The analyte was separated on a ZORBOX SB-C8 ($3.5{\mu}m$, $30mm{\times}2.1mm$ I.D.) column and analyzed in selected ion monitoring (SIM) mode with a positive ESI interface using the m/z 255 $[2M + Na]^+$ ion. The method was validated over the concentration range of $0.5-60.0\;{\mu}g$/mL under 1/9 (v/v) of acetonitrile/methanol solvent system with flow rate 0.05 mL/min. The limit of quantification (LOQ) was $0.5{\mu}g$/mL.