• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3577-3585
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• 2013

Syndecan-4 (heparan sulfate proteoglycan), biologically important in cell-to-cell interactions and tumor suppression, was studied through mutation of the GXXXG motif of its transmembrane domain (Syd4-TM), a motif which governs dimerization. The expression and purification of the mutant (mSyd4-TM) were optimized here to assess the function of the GXXXG motif in the dimerization of Syd4-TM. mSyd4-TM was obtained in M9 minimal media and its oligomerization was identified by SDS PAGE, Circular Dichroism (CD) spectroscopy, mass spectrometry and NMR spectroscopy. The mutant, unlike Syd4-TM, did not form dimers and was observed as monomers. The GXXXG motif of Syd-4TM was shown to be an important structural determinant of its dimerization.

• Journal of the Korean Magnetic Resonance Society
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• v.14 no.2
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• pp.88-104
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• 2010

Human melanocortin-4 receptor (hMC4R) has a critical role in part of energy homeostasis, and their heterozygous mutations related in genetic cause of severe human obesity. In order to study the structure and function of these membrane proteins, it is important to prepare the samples. However, the preparation of transmembrane peptide is seriously difficult and time-consuming. Overexpression and purification of membrane proteins was reported to be difficult due to their innate insoluble and toxic properties. Among the many difficulties, the most important is the difficulty in obtaining sufficient quantities of purified protein. Recently, we succeed to produce large amounts of the second transmembrane domain from the wild-type hMC4R (wt-TM2) and D90N mutant hMC4R (m-TM2) and proposed the structural difference of them in membrane-like environments. In this paper, we demonstrate the optimization procedures to express and purify wt-TM2 or m-TM2 peptides, and solution NMR studies in different detergents to get high-resolution spectra were also described.

• Food Science and Preservation
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• v.15 no.3
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• pp.385-389
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• 2008

The effects of high vanillin concentration on fresh-cut apples treated with NatureSealTM were investigated Apples were sliced, treated with 6% NatureSealTM or 6% NatureSealTM + 120 mM vanillin, packaged in polyethylene bags, and stored for 3 weeks at 4C. The L value, soluble solid level and titratable acidity of fresh-cut apples treated with NatureSealTM + 120 mM vanillin during storage were lower than those of fresh-cut apples treated with NatureSealTMonly; the growth of total aerobic bacteria, yeast and molds were also more inhibited in fresh-cut apples treated with NatureSealTM + 120 mM vanillin. These results show that the addition of 120 mM vanillin inhibits the growth of microorganism but 1m detrimental effects on the quality characteristics of fresh-cut apples treated with NatureSealTM.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.318-324
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• 2015

Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1231-1237
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• 2008

This study was conducted to investigate the functional biological effects of hot water and ethanol extracts from Taraxacum mongolicum (TM). Then, the hot water and ethanol extracts of TM were measured for total flavonoids content, total phenolics content, electron donating ability, nitrite-scavenging ability, SOD-like activity, tyrosinase inhibitory effect, and elastase inhibitory effect. Total flavonoids contents of hot water and ethanol extracts from TM were 7.80$\pm$0.97 mg/g and 9.12$\pm$0.51 mg/g, respectively, and total phenolics contents were estimated as 54.20$\pm$1.95 mg/g for water extract and 79.43$\pm$4.44 mg/g for ethanol extract. The $RC_{50}$ values for electron donating ability of hot water and ethanol extracts were 943.98 $\mu$g/mL and 309.41 $\mu$g/mL. SOD-like activity and nitrite-scavenging ability were dependent on concentration of hot water and ethanol extracts, and the activity of ethanol extract was higher than that of hot water extract. However, hot water and ethanol extracts from TM showed no inhibitory activities on the elastase and tyrosinase inhibitory activities. Based on the above results, the ethanol extract of TM seems to be the most pertinent for use as functional food and cosmetic.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.305-311
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• 2016

This study investigated the effects of a mixture of fenugreek seeds and Lespedeza cuneata extracts on testosterone synthesis in TM3 cells that were oxidatively stressed with $H_2O_2$. In order to oxidatively stress TM3 cells, the cells were treated with $50{\mu}M$ hydrogen peroxide for 4 hr in serum-free media. Yagwanmun-horopa mixture (YHM) showed neither cytotoxicity nor increment of cell proliferation in the oxidatively stressed TM3 cells in any concentration. When the cells were treated with hydrogen peroxide, testosterone levels decreased, but the testosterone level was returned to that of the control level in the presence of YHM. In order to find out the reasons for the increase of testosterone, the expression of the genes involved in the synthesis or disintegration of testosterone. On the other hand, the levels of $3{\beta}$-HSD4 and 17, 20-desmorase, which are involved in testosterone synthesis, were decreased through the use of hydrogen peroxide and were recovered through YHM treatment. Aromatase and $5{\alpha}$-reductase2, which convert testosterone to estradiol and dihydrotestosterone, respectively, were increased through the use of hydrogen peroxide, and were returned to control level through YHM treatment. These results suggest that YHM does not affect TM3 cell proliferation. However, YHM increases the expression of testosterone-synthesizing enzyme, which was decreased through oxidative stress, and decreases the expression of testosterone- converting enzyme, which was increased through oxidative stress. Therefore, it is reasonable that YHM has strong recovery activity on testosterone to normal level, even in the oxidatively stressed TM3 cells which mimics the andropause state.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1746-1750
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• 2004

The PBM ${BioSign}^{TM}$ Salmonella (PBMS) test kit based on an mmunochromatographic method was evaluated for the screening of Salmonella spp. in pure cultures, and 80, 15, and 10 artificially and naturally contaminated, and negative controlled food samples, respectively. The PBMS test involves presumptive qualitative procedures, detecting the presence of Salmonella spp. in foods within 26 h total testing period and allowing the user to release negative products 70 h earlier than the conventional methods. The PBMS test using Buffered Peptone Water and Rappaport-Vassiliadis broth was evaluated for 10 different food types for various Salmonella spp. It showed detection limits of 1 to 25 colony forming units (CFU)/25 g. No cross-reaction was observed, particularly to other gramnegative bacteria. These results indicate the PBMS test is a rapid and inexpensive procedure for the screening of Salmonella spp. present at low concentrations (1 to 25 CFU/25 g) in foods.

• Genomics & Informatics
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• v.21 no.3
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• pp.41.1-41.11
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• 2023

The Dengue virus M protein is a 75 amino acid polypeptide with two helical transmembranes (TM). The TM domain oligomerizes to form an ion channel, facilitating viral release from the host cells. The M protein has a critical role in the virus entry and life cycle, making it a potent drug target. The oligomerization of the monomeric protein was studied using ab initio modeling and molecular dynamics simulation in an implicit membrane environment. The representative structures obtained showed pentamer as the most stable oligomeric state, resembling an ion channel. Glutamic acid, threonine, serine, tryptophan, alanine, isoleucine form the pore-lining residues of the pentameric channel, conferring an overall negative charge to the channel with approximate length of 51.9 Å. Residue interaction analysis for M protein shows that Ala94, Leu95, Ser112, Glu124, and Phe155 are the central hub residues representing the physicochemical interactions between domains. The virtual screening with 165 different ion channel inhibitors from the ion channel library shows monovalent ion channel blockers, namely lumacaftor, glipizide, gliquidone, glisoxepide, and azelnidipine to be the inhibitors with high docking scores. Understanding the three-dimensional structure of M protein will help design therapeutics and vaccines for Dengue infection.

• Molecules and Cells
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• v.20 no.1
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• pp.69-73
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• 2005

The flavonoid, quercetin, is a low molecular weight substance found in apple, tomato and other fruit. Besides its antioxidative effect, quercetin, like other flavonoids, has a wide range of neuropharmacological actions including analgesia, and motility, sleep, anticonvulsant, sedative and anxiolytic effects. In the present study, we investigated its effect on mouse 5-hydroxytryptamine type 3 ($5-HT_{3A}$) receptor channel activity, which is involved in pain transmission, analgesia, vomiting, and mood disorders. The $5-HT_{3A}$ receptor was expressed in Xenopus oocytes, and the current was measured with the two-electrode voltage clamp technique. In oocytes injected with $5-HT_{3A}$ receptor cRNA, quercetin inhibited the 5-HT-induced inward peak current ($I_{5-HT}$) with an $IC_{50}$ of $64.7{\pm}2.2{\mu}M$. Inhibition was competitive and voltage-independent. Point mutations of pre-transmembrane domain 1 (pre-TM1) such as R222T and R222A, but not R222D, R222E and R222K, abolished inhibition, indicating that quercetin interacts with the pre-TM1 of the $5-HT_{3A}$ receptor.