• Journal of Life Science
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• v.27 no.12
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• pp.1410-1414
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• 2017

Escherichia coli tryptophan synthase (TS) contains ${\alpha}_2{\beta}_2$, which catalyzes the final two steps in Trp biosynthesis. A molecular tunnel exists between the two active sites of ${\alpha}$ and ${\beta}$ subunits in TS. Via intersubunit communication, TS increases catalytic efficiency, including substrate channeling. The ${\beta}$ subunit of TS is composed of two domains, one of which, the COMM (communication) domain, plays an important role in intersubunit communication. The ${\alpha}$ subunit has a TIM barrel structure. This protein has functional regions at the C terminal of ${\beta}$ pleated sheets and in its loop regions. Three regions of the ${\alpha}$ subunit (${\alpha}L6$ [${\alpha}-loop$ L6], ${\alpha}L2$, and ${\alpha}L3$) are implicated in intersubunit communication. In the present study, conformational changes in ${\alpha}L6$ were monitored by measuring the sensitivity of mutant proteins in these regions to trypsin. The addition of a ${\alpha}$ subunit-specific ligand, D,L-${\alpha}$-glycerophosphate (GP), partially restored the sensitivity of mutant proteins to trypsin. In contrast, the addition of the ${\beta}$ subunit-specific ligand L-serine (Ser) resulted in varied sensitivity to trypsin, with an increase in PT53 (substitution of Pro with Thr at residue 53) and DG56, decrease in NS104 and wild type, and no change in GD51 and PH53. This finding may be related to several reaction intermediates formed under this condition. The addition of both GP and Ser led to a highly stable state of the complex. The present results are consistent with the current model. The method used herein may be useful for screening residues involved in intersubunit communication.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.480-487
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• 1997

Vitellogenin (Vg) was purified from plasma of $estradiol-17\beta(E_2)-treated$ spotted flounder, verasper variegatus, by preripitation with cold distilled water, followed by fractionation using a Sepharose CL-6B column chromatography. $E_2-induced$ protein was identified as Vg by SDS-PAGE and western blot analysis. The molecular weight of the purified Vg was estimated 175 kD as determined by SDS-PAGE. In order to measure the Vg level, monoclonal antibodies against Vg were produced by hybridoma technique. Purified Vg was immunized into Balb/c mice and then the spleen cells from mice were fused with NS-1 myeloma cells. The hybridoma cells were screened by enzyme-linked immunosorbent assay (WLISA) and subcloned by limiting dilution. The hybridoma clones which secreted antibodies highly reactive to the purified Vg were designated as 4D6. Its specificity was demonstrated by western blot from plasma of untreated, $E_2-treated$ male fish, and purified Vg.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.64-71
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• 1999

Purpose : The protective effects of dietary protein on the progression of renal failure were studied in subtotally nephrectomized rats. Methods : Treatment groups were as follows; 5/6 nephrectomy and a normal protein ($18.5\%$) diet (NP); 5/6 nephrectomy and a low protein ($6\%$) diet (LP): 5/6 nephrectomy, a normal protein diet and converting enzyme inhibitor, enalapril (NPE): 5/6 nephrectomy, a low protein diet and enalapril (LPE). Both diets were isocaloric and had the same phosphorus content. Proteinuria, remnant kidney weight, mesangial matrix expansion score and glomerular volume were assessed at 4, 12 and 16 weeks after renal ablation. Results : LP and NP developed progressive hypertension. Eight weeks after surgery, LPE and NPE controlled hypertension. LP, LPE, and NPE had significantly less proteinuria than NP at 16 weeks (P<0.05). Kidney weight in LP were markedly less enlarged than NP (P<0.05). There was no difference in kidney weight between LPE and NPE. At 12 and 16 weeks the mesangial matrix expansion score was significantly less in LP, LPE, and NPE compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume was significantly less in LP compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume in LPE was significantly less compared to NPE. Conclusion : Dietary protein restriction afforded considerable protection from renal injury in the rat remnant kidney model. During the enalapril treatment, there was no additional protective effect of dietary protein restriction against the development of renal lesions.

• IMMUNE NETWORK
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• v.3 no.3
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• pp.201-210
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• 2003

Objective: The role of prostaglandin $E_2$ (PGE2) in the etiopathogenesis of immune and inflammatory diseases has become the subject of recent debate. To determine the role of PGE2 in rheumatoid arthritis (RA), we tested the effect of exogenous PGE2 on the production of cyclooxygenase-2 (COX-2) by rheumatoid synoviocytes. Methods: Fibroblast-like synoviocytes (FLS) were prepared from the synovial tissues of RA patients, and cultured in the presence of PGE2. The COX-2 mRNA and protein expression levels were determined by RT-PCR and Western blot analysis, respectively. The PGE2 receptor subtypes in the FLS were analyzed by RT-PCR. Electrophoretic mobility shift assay (EMSA) was used to measure the NF-${\kappa}B$ binding activity for COX-2 transcription. The in vivoeffect of PGE2 on the development of arthritis was also tested in collagen induced arthritis (CIA) animals. Results: PGE2 ($10^{-11}$ to $10^{-5}M$) dose-dependently inhibited the expression of COX-2 mRNA and the COX-2 protein stimulated with IL-$1{\beta}$, but not COX-1 mRNA. NS-398, a selective COX-2 inhibitor, displayed an additive effect on PGE2-induced COX-2 downregulation. The FLS predominantly expressed the PGE2 receptor (EP) 2 and EP4, which mediated the COX-2 suppression by PGE2. Treatment with anti-IL-10 monoclonal antibodies partially reversed the PGE2-induced suppression of COX-2 mRNA, suggesting that IL-10 may be involved in modulating COX-2 by PGE2. Experiments using an inducer and an inhibitor of cyclic AMP (cAMP) suggest that cAMP is the major intracellular signal that mediates the regulatory effect of PGE2 on COX-2 expression. EMSA revealed that PGE2 inhibited the binding of NF-${\kappa}B$ in the COX-2 promoter via a cAMP dependent pathway. In addition, a subcutaneous injection of PGE2 twice daily for 2 weeks significantly reduced the incidence and severity of CIA as well as the production of IgG antibodies to type II collagen. Conclusion: Our data suggest that overproduced PGE2 in the RA joints may function as an autocrine regulator of its own synthesis by inhibiting COX-2 production and may, in part, play an anti-inflammatory role in the arthritic joints.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.228.2-228.2
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• 2015

We have developed a TOF-MEIS system using 70~100 keV He+. A TOF-MEIS system was designed and constructed to minimize the ion beam damage effect by utilizing a pulsed ion beam with a pulse width < 1 ns and a TOF delay-line-detector with an 120 mm diameter and a time resolution of 180 ps. The TOF-MEIS is an useful tool for interfacial analysis of the composition and structure of nano and bio systems. Our recent applications are reported. We investigated the effect with Polyaspartic Acid (pAsp) and Osteocalcin on the initial bone growth of calcium hydroxyl appatite on a carboxyl terminated surface. When pAsp is not added to the self-assembled monolayers of Ca 2mM with Phosphate 1.2 mM, the growth procedure of calcium hydroxyl appatite cannot be monitored due to its rapid growth. When pAsp is added to the SAMs, the initial grow stage of the Ca-P can be monitored so that the chemical composition and their nucleus size can be analyzed. Firstly discovered the existence of 1-nm-sized abnormal calcium-rich clusters (Ca/P ~ 3) comprised of three calcium ions and one phosphate ion. First-principles studies demonstrated that the clusters can be stabilized through the passivation of the non-collagenous-protein mimicking carboxyl-ligands, and it progressively changes their compositional ratio toward that of a bulk phase (Ca/P~1.67) with a concurrent increase in their size to ~2 nm. Moreover, we found that the stoichiometry of the clusters and their growth behavior can be directed by the surrounding proteins, such as osteocalcin.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.137-145
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• 2007

The effect of cadmium chloride $(CdCl_2)$ on the expression of E-cadherin was examined in bEnd.3 mouse brain endothelial cells. $CdCl_2$ induced $PGE_2$ release, which were blocked by non-steroidal antinflamatory drugs (NSAIDs) such as indomethacin and NS398 indicating the expression of COX-2 might contribute to $PGE_2$ production. $CdCl_2$ decreased the expression of E-cadherin, but not VE-cadherin at levels of mRNA and protein. Reduced expression level of E-cadherin was restored by NSAIDs, which was reversed by the addition of $PGE_2$. $CdC_2$-induced decrease of E-cadherin level was also recovered by antioxidants including N-acetylcyteine (NAC) and trolox. Together with previous report which showed $CdCl_2$ induced COX-2 expression in a cellular oxidative stress dependent manner, these data suggest that $CdCl_2$ decreases E-cadherin expression through induction of cellular oxidative stress and in turn COX-2 expression in brain endothelial cells.

• BMB Reports
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• v.40 no.1
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• pp.95-99
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• 2007

Bovine coding region single nucleotide polymorphisms located proximal to quantitative trait loci were identified to facilitate bovine QTL fine mapping research. A total of 692,763 bovine SNPs was extracted from 39,432 UniGene clusters, and 53,446 candidate SNPs were found to be a depth >3. In order to validate the in silico SNPs experimentally, 186 animals representing 14 breeds and 100 mixed breeds were analyzed. Genotyping of 40 randomly selected candidate SNPs revealed that 43% of these SNPs ranged in frequency from 0.009 to 0.498. To identify non-synonymous SNPs and to correct for possible frameshift errors in the ESTs at the predicted SNP positions, we designed a program that determines coding regions by protein-sequence referencing, and identified 17,735 nsSNPs. The SNPs and bovine quantitative traits loci informations were integrated into a bovine SNP data: BcSNPdb (http://snugenome.snu.ac.kr/BtcSNP/). Currently there are 43 different kinds of quantitative traits available. Thus, these SNPs would serve as valuable resources for exploiting genomic variation that influence economically and agriculturally important traits in cows.

• Molecules and Cells
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• v.44 no.9
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• pp.688-695
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• 2021

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a global health concern. Various SARS-CoV-2 vaccines have been developed and are being used for vaccination worldwide. However, no therapeutic agents against coronavirus disease 2019 (COVID-19) have been developed so far; therefore, new therapeutic agents are urgently needed. In the present study, we evaluated several hepatitis C virus direct-acting antivirals as potential candidates for drug repurposing against COVID-19. Theses include asunaprevir (a protease inhibitor), daclatasvir (an NS5A inhibitor), and sofosbuvir (an RNA polymerase inhibitor). We found that asunaprevir, but not sofosbuvir and daclatasvir, markedly inhibited SARS-CoV-2-induced cytopathic effects in Vero E6 cells. Both RNA and protein levels of SARS-CoV-2 were significantly decreased by treatment with asunaprevir. Moreover, asunaprevir profoundly decreased virion release from SARS-CoV-2-infected cells. A pseudoparticle entry assay revealed that asunaprevir blocked SARS-CoV-2 infection at the binding step of the viral life cycle. Furthermore, asunaprevir inhibited SARS-CoV-2 propagation in human lung Calu-3 cells. Collectively, we found that asunaprevir displays broad-spectrum antiviral activity and therefore might be worth developing as a new drug repurposing candidate for COVID-19.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.17-23
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• 2018

The objective of this study was to compare physicochemical, microbial, and antioxidant properties of domestic and imported wheat kernels for bread making. Two domestic (JK1, 2) and three imported (ND, DNS, and CWRS) kernels were compared. Domestic kernels had higher moisture contents, and lower ash and protein contents (p<0.05). In grain characteristics, JK1 had 13.62% of damaged kernels, which was the highest among the samples (p<0.05). JK2 was similar to imported kernels in the ratio of sound kernels, foreign materials, and damaged kernels. Kernel size of JK1, 2 was larger than the imported kernels; therefore, kernels area and perimeter were higher by the image analyzer. Domestic kernels hid lower total aerobic counts the imported kernels (p<0.05). Domestic kernels and DNS had no yeast, while NS and CWRS had yeast in kernels. DNS (3.08 mg gallic acid equivalent (GAE)/g) had the highest total polyphenol content (TPC), followed by JK1 (2.81 mg GAE/g). JK2 had the lowest amount of TPC as 2.26 mg GAE/g. Total flavonoid content (TFC) was the highest in DNS as 0.44 mg catechin equivalent (CE)/g and JK2 was the lowest as 0.12 mg CE/g. Domestic wheat kernels had lower protein content and lightness than the imported wheat kernels so that flour from domestic wheat kernels may have lower quality for baking.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.335-336
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• 1996

Artemisinin, a new antimalarial to treat patients infected with strains of Plasmodium jalciparum, derived from the plant Artemisia annua Linn, has immunopharmacologic actions such as enhence the PHA -induced lymphocyte transformation rate, increased the weight of spleen but reduced the weight of thymus, reduced phagocytic function of peritoneal macrophage, remarkably reduced the level of serum IgG and hemolysin fonning capacity (sentitized with SRBC), inhibited the activity of Ts cells of donor mice by supraoptimal immunuization(SOI), but enhenced activity of Ts cells of recipient mice by SOI. These results suggested that Ts cells may be the target cells of artemisinin. To the serum complement C3 level of plasmodium berghei-infeted mice, artemisinin (i. m,) could remarkly increase it. The artemisinin also obviously reduced the prostaglandin E(PGE) in the mouse hind paw swelling induced by carrageenin. Numerous studies have demonstrated that pharmacologic doses of PGE attenuate the development of immunocomplex nephritis. Some autologous immune mechanisms may be invoolved In the pathogensis of some types of glomurulonephritis. Glomerular abnormalities can be induced in animals by variety of immunological manipulations. The resulting disorder has many clinical and pathogical similarities to the disease in human. Our purpose was therefore to test the ability of the artemisinin to lessen the severity of rabbit IgG accelerated nephrotoxic serum glomerulonephritis in mice model. Mice which had treated with rabbit IgG and NTS, administrated with saline, showed Significant inceases of urinary protein, cholesterol level, and decrease of serum albumin in NS group. On the contrary, By i.g. adminstration of artemisinin at dose of 12.5, 25 and 50 mg/kg for 14 days after NTS injection, shown that artemisinin inhibited the nephritic changes in some parameters by means of urinary protein(p<0.05, p<0.01) and serum choleterol(p<0.05, p<0.01) and albumin (p<0.05, p<0.01), blood urea nitrogen (p<0.05, p<0.01), serum albumin(p<0.05, p<0.01); Cyclophosphamide(i.p. 10mg/kg for 14d) had almost same effect as the artemisinin had. Morphological studies shown that The picture of kidney from the mouse with NTS-nephritis accerated with rabbit IgG, treated with i.g. saline as the control, the mesangiocapillary were enlarged and proliferated; There were inflammatory cells infiltrating around the glomeruli; The ethelial cell were proliferated in the wall of Bowman's capsule. Histopatholological picture of kidney from the NTS-nephritis accerated with rabbit IgG mouse treated with i.p. 10mg/kg cyclophosphamide as the positive control. No siginicant histopathological evidence were found. Treaded with i.p. 12.5mg/kg artemisinine, the picture shown that mesangiocapillary were lightly proliferated; There were inflammatory cells infiltrating around the glomeruli; Treaded with i.p. 25mg/kg artemisinine, The picture shown that the mesangiocapillary were lightly proliferated; Treaded with i.p. 50mg/kg artemisinine, The picture shown that both the mesangiocapillary proliferated and the inflammatory cells infiltrating around the glomeruli are less than treated with saline, 12.5 and 25 mg/kg artemisinine. On the basis of these studies we conclude that the artemisinin can relieve pathological change caused by NTS-nephritis aacerated with rabbit IgG.