• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.227-232
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• 2015

A microarray study has been employed to understand changes of gene expression in E. coli KD43162 resistant to ampicillin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, cefazolin, cefepime, aztreonam, imipenem, meropenem, gentamicin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, fosfomycin, and trimethoprim-sulfamethoxazole except for amikacin using disk diffusion assay. Using Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and MALDI-TOF MS analyses, 36 kDa of outer membrane proteins (OMPs) was found to be deleted in the multidrug resistant E. coli KD 43162. Microarray analysis was used to determine up- and down-regulated genes in relation to multidrug resistant E. coli KD43162. Among the up-regulated genes, these genes were corresponded to express the proteins as penicillin-binding proteins (PBPs), tartronate semialdehyde reductase, ethanolamine utilization protein, shikimate kinase I, allantoinase, predicted SAM-dependent methyltransferase, L-glutamine: D-fructose-6-phosphate aminotransferase (GFAT), phospho-glucosamine mutase, predicted N-acetylmannosamine kinase, and predicted N-acetylmannosamine-6-P epimerase. Up-regulation of PBPs, one of primary target sites of antibiotics, might be responsible for the multidrug resistance in E. coli with increasing amount of target sites. Up-regulation of GFAT enzyme may be related to the up-regulation of PBPs because GFAT produces N-acetylglucosamine, a precursor of peptidoglycans. One of GFAT inhibitors, azaserine, showed a potent inhibition on the growth of E. coli KD43162. In conclusion, up-regulation of PBPs and GFATs with the loss of 36 kDa OMP refers the multidrug resistance in E. coli KD 43162.

• Journal of Pharmaceutical Investigation
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• 제36권4호
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• pp.277-282
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• 2006

Lisinopril is one of the angiotensin-converting enzyme inhibitors, which have been used for treatment of hypertension and heart failure. The aim of this study was to evaluate the bioequivalence of two lisinopril tablet, $Lisihexal^{\circledR}$ and $Zestril^{\circledR}$ as a test and reference, respectively. The study was came out on 28 healthy male Korean volunteers in $2{\times}2$ crossover design. An analytical method with LC-MS-MS was developed for the quantification of lisinopril and enalapril(IS) using SPE method. The condition was selective, sensitive and precise in human plasma, that was enough for the pharmacokinetic study of lisinopril. The pharmacokinetic parameters such as $AUC_t,\;AUC_{inf},\;C_{max},\;T_{max}\;and\;t_{1/2}$ were calculated and ANOVA test was used for the statistical analysis of the parameters using log transformed $AUC_t,\;AUC_{inf}\;and\;C_{max}$. $t_{1/2}$ of test and reference drugs were calculated $11.4{\pm}5.1\;and\;16.1{\pm}9.9\;hr$, respectively. The 90% confidence intervals of $AUC_t,\;AUC_{inf}\;and\;C_{max}$ were log 0.9245$\sim$log 1.0603, log 0.9270$\sim$log 1.0601 and log 0.9548$\sim$log 1.1009, within the acceptable range of log 0.8 to log 1.25 by KFDA bioequivalence criteria. Two medications of lisinopril were evaluated bioequivalent and thus may be prescribed interchangeably.

• Journal of Animal Science and Technology
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• 제51권6호
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• pp.527-536
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• 2009

A potent protein degrading bacterium was isolated from soil samples of different environments. Polyphasic taxonomic studies and phylogenetic 16S rRNA sequence analyses led to identify the isolate IB No. 11 as a strain of Bacillus subtilis. The isolated strain was recognized to produce protease constitutively, and the maximum production (1.64 units/ml) was attained in a shake flask culture when the isolate was grown at $40^{\circ}C$, for 32 h in basal medium supplemented with starch (0.25%) and gelatin (1.25%) as sole carbon and nitrogen source, respectively. The optimum pH and temperature for the protease activity were determined to be pH 7.0 and $50^{\circ}C$, respectively. $Ca^{2+}$ and $Mn^{2+}$ enhanced remarkably the protease activity but neither showed positive effect on the protease's thermal stability. In addition, it was observed that the protease was fairly stable in the pH range of 6.5-8.0 and at temperatures below $50^{\circ}C$, and it could be a good candidate for an animal feed additive. The inhibition profile of the protease by various inhibitors indicated that the enzyme is a member of serine-proteases. A combination of UV irradiation and NTG mutagenesis allowed to develop a protease hyper-producing mutant strain coded as IB No. 11-4. This mutant strain produced approximately 3.23-fold higher protease activity (6.74 units/mg) than the parent strain IB No. 11 when grown at $40^{\circ}C$ for 32h in the production medium. The protease production profile of the selected mutants was also confirmed by the zymography analysis.

• 약학회지
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• 제53권4호
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• pp.222-227
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• 2009

Human topoisomerase I (Topo I) plays a pivotal role in cell replication, transcription and repair and, therefore, is an important anti-cancer target. 20S-camptothecin (CPT) is a representative Topo I inhibitor. Compounds belonging to CPT family inhibit the religation step of Topo I-DNA by binding to the DNA cleavage site. Computational docking studies with Surflex-Dock were carried out to investigate the binding modes between Topo I-DNA binary complex structure and the ligand such as 20S-CPT and 9,10-substituted 20S-CPT analogues. The docking results demonstrated that most of the compounds with $IC_{50}$ value under $0.5{\mu}M$ intercalated exactly between the -1 and +1 DNA bases, deeply toward the cleavage site. The complex was stabilized by hydrogen-bonding and hydrophobic interactions with both the enzyme and the DNA. The compounds with $IC_{50}$ value above $0.5{\mu}M$ were poorly docked and did not intercalate. In addition, the docking results confirmed the overall correlation between the $IC_{50}$ values and docking scores, indicating the possible use of the modeling for the prediction of biological activity and design of potential inhibitors.

• 한국동물학회지
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• 제36권3호
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• pp.367-372
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• 1993

재생쥐간에서 분리한 topoisomerase II에서 protein kinase 활성이 발견되었다. ,topo II 활성 및 kinase 활성은 hydroxyapatite, phosphocellulose, double strand DNA cellulose chromatography 등의 순수 분리 과정 중에도 서로 분리되지 않았으며 glycerol gradient sedimentation 분석에서도 같은 분획에서 활성이 존재하였다. Kinase는 topo II 저해제인 N-ethylmaleimide와 novobiocin 등에 의해 그 활성이 저해되었다. 그러나 이러한 증거들 만으로 kinase 활성이 topo II가 아닌 다른 polypeptide에 의한 것일 가능성을 완전히 배제 할 수는 없다. Topo II와 결합된 kinase 활성에는 Mg++가 절대적으로 필요하였으며 다른 일가 또는 이가 이온으로는 그 효과가 대체되지 않았다. Histone H1은 kinase 활성을 증가 시키며 또 kinase에 의해 강하게 인산화된다. 이러한 효과는 다른 histone 류 및 casein 등에 의해 대체되지 않았다.

• International Journal of Oral Biology
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• 제30권3호
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• pp.85-90
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• 2005

Homeostatic pH is very important for various cellular processes, including metabolism, survival, and death. An imbalanced-pH might induce cellular acidosis, which is involved in many abnormal events such as apoptosis and malignancy. One of several factors contributing to the onset of metabolic acidosis is the production of lactate and protons by lactate dehydrogenase (LDH) in anaerobic glycolysis. LDH is an important enzyme that catalyzes the reversible conversion of pyruvate to lactate. This study sought to examine whether decreases in extracellular pH induce apoptosis of CHO cells, and to elucidate the role of mitogen-activated protein kinases (MAPKs) in acidification-induced apoptosis. To test apoptotic signaling by acidification we used CHO dhfr cells that were sensitive to acidification, and CHO/anti-LDH cells that are resistant to acidification-induced apoptosis and have reduced LDH activity by stable LDH antisense mRNA expression. In the present study, cellular lactic acid-induced acidification and the role of MAPKs signaling in acidification-induced apoptosis were investigated. Acidification, which is caused by $HCO{_3}^-$-free conditions, induced apoptosis and MAPKs (ERK, JNK, and p38) activation. However, MAPKs were slightly activated in acidic conditions in the CHO/anti-LDH cells, indicating that lactic acid-induced acidification induces activation of MAPKs. Treatment with a p38 inhibitor, PD169316, increased acidification-induced apoptosis but apoptosis was not affected by inhibitors for ERK (U0126) or JNK (SP600125). Thus, these data support the hypothesis that activation of the p38 MAPK during acidification-induced apoptosis contributes to cell survival.

• Journal of Pharmaceutical Investigation
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• 제28권1호
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• pp.25-33
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• 1998

Intestinal absorption of ${\beta}-lactam$ antibiotics and angiotensin converting enzyme(ACE) inhibitors has been shown to use the carrier-mediated transport system. In vitro experiments have established that the efficacy of uptake by enterocytes depends on an inwardly directed proton gradient. It was suggested that benazepril was mediated by tripeptide transport system and that amoxicillin was transported by dipeptide transport carrier. The aim of this study is to assess the influence of amoxicillin on the intestinal absorption of benazepril using in vitro diffusion chamber and in situ single pass perfusion technique in the rat in order to elucidate whether the above transport systems are competitive or not. We obtained the gastrointestinal pemeability coefficient of amoxicillin, benazepril and both of them using in vitro diffusion chamber. And also the gastrointestinal absorption clearance of amoxicillin, benazepril and both of them using in situ single-pass perfusion method at steady state were calculated. Amoxicillin and benazepril were analyzed by HPLC. The results by the use of diffusion chamber in vitro indicated that the apparent intestinal permeability coefficient of benazepril was significantly(p<0.01) decreased by amoxicillin(45.2%) and vice versa significantly(p<0.01) decreased(89.1%). The results by the in situ gastrointestinal single-pass perfusion method indicated that the intestinal absorption clearance of benazepril was significantly(p<0.05) decreased by amoxicillin (40.2%) and vice versa significantly(p<0.05) decreased(54.8%). These results might suggest that they share the same peptide carrier pathway for oral absorption.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1227-1233
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• 2015

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptors, which mainly occurs to VEGF receptor 2 (VEGFR-2), a kinase insert domain-containing receptor. Therefore, the disruption of VEGFR-2 signaling provides a promising therapeutic approach for the treatment of cancer by inhibiting abnormal or tumorinduced angiogenesis. To explore this potential, we expressed the catalytic domain of VEGFR-2 (VEGFR-2-CD) as a soluble active kinase in Escherichia coli. The recombinant protein was purified and the VEGFR-2-CD activity was investigated. The obtained VEGFR-2-CD showed autophosphorylation activity and phosphate transfer activity comparable to the commercial enzyme. Furthermore, the IC₅₀ value of known VEGFR-2 inhibitor was determined using the purified VEGFR-2-CD. These results indicated a possibility for functional and economical VEGFR-2-CD expression in E. coli to use for inhibitor screening.

• 한국균학회지
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• 제38권2호
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• pp.167-171
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• 2010

The present study aims to evaluate Cordyceps militaris water extract (CMWE) with a view to develop melanogenesis inhibitors. Inhibitory activities of CMWE against tyrosinase, L-DOPA(L-3,4-dihydroxyphenylalanine) oxidation, and melanin biosynthesis in B16 mouse melanoma cells were investigated. CMWE, at $5000\;{\mu}g/ml$, inhibited tyrosinase activity of 71% and DOPA oxidation of 40% as reacting with L-DOPA. Furthermore, B16 mouse melanoma cell survived over 50% from low to high dose on MTT assay, and CMWE markedly inhibited (> 50%) melanin synthesis at $5000\;{\mu}g/ml$. The inhibitory effect of CMWE on melanogenesis was attributed to enhancement of tyrosinase degradation. Key enzyme of melanin biosynthesis is tyrosinase which catalyses a beginning step from tyrosine to DOPA quinine and melanin formation step, respectively. These results indicated that CMWE may be a potential source of novel whitening agents for cosmetic or therapeutic application.

• Natural Product Sciences
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• 제22권2호
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• pp.111-116
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• 2016

Phytochemical investigation of the stems of Pueraria lobata (Wild) Ohwi (Leguminosae), led to the isolation of eighteen known compounds: ${\beta}$-amyrone (1), (+)-pinoresinol (2), (+)-syringaresinol (3) $(+)-syringaresinol-O-{\beta}-{\small{D}}-glucoside$ (4), (+)-lariciresinol (5), (-)-tuberosin (6), naringenin (7), liquiritigenin (8), isoliquiritigenin (9) genistein (10), daidzein (11) daidzin (12) daidzein 4',7-diglucoside (13) 2,4,4'-trihydroxy deoxybenzoin (14), S-(+)-1-hydroxy-3-(4-hydroxyphenyl)-1-(4-hydroxy-2-methoxy-phenyl)propan-2-one (15), methyl $2-O-{\beta}-{\small{D}}-glucopyranosylbenzoate$ (16), pyromeconic acid $3-O-{\beta}-{\small{D}}-glucopyranoside$ 6'- (O-4''-hydroxy-3-methoxybenzoate) (17), and allantion (18). The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of those data with previously published results. The effects of isolated compounds on mushroom tyrosinase enzymatic activity were screened. The results indicated that, chloroform extract of P. lobata stems turned out to be having tyrosinase inhibitory effect, and only compounds 5, 8, 9, and 11 showed enzyme inhibitory activity, with $IC_{50}$ values of $21.49{\pm}4.44$, $25.24{\pm}6.79$, $4.85{\pm}2.29$, and $17.50{\pm}1.29{\mu}M$, respectively, in comparison with these of positive control, kojic acid ($IC_{50}\;12.28{\pm}2.72{\mu}M$). The results suggest that P. lobata stems extract as well as its chemical components may represent as potential candidates for tyrosinase inhibitors.