• Korean Journal of Microbiology
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• v.40 no.4
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• pp.269-274
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• 2004

Serratia proteamaculans isolated from the midgut of a spider formed big halos around the bacterial colonies, indicating that the bacterial strain produces an extracellular protease. Activity staining of the extracellular pro­tein fractions using zymogram also demonstrated that the major protein with an estimated molecular mass of 52 kDa contained a high proteolytic activity. The protease was purified to near electrophoretic homogeneity from the culture supernatant after filtration and ion exchange and size exclusion chromatography. The purified enzyme had a relatively high proteolytic activity between pH 6.0 and 10.0 and at broad temperature range. The proteolytic activity of the enzyme was not inhibited by phenylmethylsulfonyl fluoride but strongly inhibited by 1, 10-phenanthroline and EDTA. The activity also was dependent on the presence of $Ca^{++}\;and\;Zn^{++}$ ions. These observations indicate that the enzyme is a metalloprotease.

• Journal of Life Science
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• v.25 no.6
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• pp.631-637
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• 2015

Streptavidin, a protein produced by Streptomyces avidinii, strongly binds up to four molecules of vitamin H, d-biotin exhibiting the dissociation constant of about 10⁻¹⁵ M. This strong binding affinity has been applied for detection and characterization of numerous biological molecules suggesting expression and purification of functional streptavidin should be very useful for the application of this streptavidin-biotin interaction. To express a soluble streptavidin in Escherichia coli, We synthesized streptavidin genes and cloned into pET-22b plasmid, which uses T7 RNA polymerase/T7 promoter expression systems containing pelB leader for secretion into periplasmic space and six polyhistidine tags at C-terminus for purification of expressed proteins. Although streptavidin is toxic to Escherichia coli due to strong biotin binding property, streptavidin was expressed very sufficiently in a range of 10-20 mg/ml. In SDS-PAGE, the size of purified protein was shown as 17 kDa in denatured condition (boiling) and 68 kDa in native condition (without boiling) suggesting tetramerization of monomeric subunit by non-covalent association. Further analysis by size-exclusion chromatography supported streptavidin’s tetrameric structure as well. In addition, soluble streptavidin detected biotinylated proteins in westernblot indicating its functional activity to biotin. Taken these results together, it concluded that our simple expression system was able to show high yield, homotetrameric formation and biotin binding activity analogous to natural streptavidin.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.309-321
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• 1987

For the investigation of microbiological and immunological specificity of Bacteroides gingivalis, Bacteroides gingivalis were isolated, enumerated and characterized from 13 Korean rapidly progressive periodontitis and 7 healthy control by anaerobic culture technique. The total proportion of black-pigmented Bacteroides from Korean R.P.P. patients and healthy control were 8.78% and 0.92%, respectively, among total isolated black-pigmented Bacteroides. In antibiotic susceptibility test, Bacteroides gingivalis isolated from R.P.P. patients were sensitive to Ampicillin and Tetracycline, and resistant to Gentamicin and Erythromycin in disc diffusion method. In antibiotic broth dilution method, the minimum inhibitory concentration(MIC) to Bacteroides gingivalis was 2 unit/ml of Penicillin and $0.25{\sim}1{\mu}g/ml$ of Tetracycline, respectively. The concentration of serum IgG in rapidly progressive periodontitis patients were sigificantly higher than that of healthy control, and concentration of diluted gingival crevicular IgG has not any significant differences between two groups. Serum and gingival crevicular IgG antibody to Bacteroides gingivalis were significantly higher titer in rapidly progressive periodontitis patients to compare with healthy control. The lipopolysaccharide profiles of 2 Korean B. gingivalis in silver stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis were similar to type strains of B. gingivalis and typical LPS band were appeared around the 24-Kd molecular weight. Immunodiffusion test and immunoelectrophoresis of the L.P.S. extracted from 2 Korean B. gingivalis and 2 kinds of type strains of B. gingivalis showed that B. gingivalis Korean-1 was reacted identically to B. gingivalis ATCC 33277. In trypsin and ${\alpha}$-glucosidase activity test of 2 Korean B. gingivalis, both of them revealed positive trypsin and negative ${\alpha}$-glucosidase activity, respectively. These investigation suggested that B. gingivalis is important pathogenic plaque bacteria for the pathogenesis of periodontitis and further study is needed to purify and characterize of the species-specific antigens of this organisms to develop monoclonal antibody and potential diagnostic reagents.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.165-178
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• 1988

In this study, the effect of single or repeated (daily for 7 or 14 days) electroconvulsive shock (ECS) on central and peripheral opiate system and modification of the actions of ECS by several psychoactive drugs were investigated in the rat. Repeated ECS caused increase of Met-enkephalin content and decrease of Bmax of specific $[^3H]$imorphine binding in the rat brain. These effects were persisted more than 7 days after the last ECS, but single ECS failed to show these effects. However, ${\beta}-endorphin$ content was decreased in midbrain preparation and increased in plasma by repeated or single ECS. These phenomenon was seen shortly after the last ECS. After ECS-induced seizure was prevented by phenobarbital, ECS-induced increase in Met-enkephalin content was significantly attenuated. Imipramine or pargyline did not affect the action of repeated ECS. On the other hand, reserpine, chlorpromazine or haloperidol which were classified as neuroleptic antipsychotics, augmented the ECS-induced changes of central and peripheral opiate parameters. Furthermore, in groups received repeated ECS, changes of Bmax of specific $[^3H]-morphine binding$ binding was inversely correlated with changes of Met-enkephalin contents, but not with changes of ${\beta}-endorphin$ contents. From these results, it is inferred that the central or peripheral opioidergic system may be involved in the therapeutic and/or adverse effects of ECS which also can be influenced by some psychoactive drugs.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.769-774
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• 1997

Non-neuronal high affinity binding sites for benzodiazepines have been found in many peripheral tissues including cardiac muscle and vascular smooth muscle, and have been designated as 'peripheral benzodiazepine receptor'. Benzodiazepines have been shown to induce relaxation of the ileal, vesical, and uterine smooth muscles. However, it is still unclear about possible involvement of peripheral benzodiazepine receptor on the contractility of trachealis muscle. This study was performed to investigate the role of the peripheral benzodiazepine receptor on the contractility of canine trachealis muscle. Canine trachealis muscle strips of 15 mm long were suspended in an isolated organ bath containing 1 ml of physiological salt solution maintained at $37^{\circ}C$, and aerated with $95%\;O_2/5%\;CO_2$. Isometric myography was performed, and the results of the experiments were as follows: Ro5-4684, FGIN-1-27 and clonazepam reduced a basal tone of isolated canine trachealis muscle strip concentration dependently, relaxant actions of RoS-4684 and FGIN-1-27 were antagonized by PK11195, a peripheral benzodiazepine receptor antagonist. Flumazenil, a central type antagonist, did not antagonize the relaxant action of Peripheral type agonists. Saturation binding assay of [3H]Ro5-4864 showed a high affinity$(Kd=5.33{\pm}1.27nM,\;Bmax=\;867.3{\pm}147.2\;fmol/mg\;protein)$ binding site on the canine trachealis muscle. Ro 5-4684 suppressed the bethanechol-, 5-hydroxyoyptamine- and histamine- induced contractions. Platelet activating factor (PAF) exerted strong and prolonged contraction in trachealis muscle strip. Strong tonic contraction by PAE was attenuated by Ro 5-4684, but not by WEB 2086, a PAF antagonist. Based on these results, it is concluded that the peripheral benzodiazepine receptor mediates the inhibitory regulation of contractilty of canine trachealis muscle.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.341-349
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• 2005

Soil adsorption study was carried out to define the mobility of pesticides and to evaluate leaching potential in soils. Nine pesticides including metolcarb, molinate, fenobucarb, isazofos, diazinon, fenitrothion, dimepiperate, parathion and chlorpyrifos-methyl were subjected to adsorption experiment for four types of soils, such as upland, paddy, forest and volcanic ash soil. Based on Koc values, metolcarb and molinate were classified as mobile, fenobucarb as mobile or moderately mobile isazofos as moderately mobile, diazinon, fenitrothin, dimepiperate, and parathion as slightly or moderately mobile and chlorpyrifos-methyl as slightly mobile. Two evaluation methods, Groundwater Ubiquity Score (GUS) index and standard indices of soil-chemical adsorption and biodegradation (half-life), were used for the estimation of pesticide leaching potential. Leachabilities of metolcarb, molinate and fenobucarb were evaluated as high, and isazofos, dimepiperate and diazinon as a little potential, while fenitrothion, parthion and chlorpyrifos-methyl showed very low leaching potential. The leaching potential of pesticides was determined on the basis of intrinsic properties of the pesticides and the soil properties. Among the soil properties, organic matter gave a great influence on the leachability in soil. Therefore, leachabilities of the pesticides used were expected less in Sineom soil with relatively higher organic matter than Gangseo, Jungdong and Yesan soil with lower organic matter.

• Toxicological Research
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• v.17
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• pp.47-57
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• 2001

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and its pathology is characterized by the presence of numerous numbers of senile plaques and neurofibrillary tangles. Several genetic and transgenic studies have indicated that excess amount of $\beta$-amyloid protein (A$\beta$) is produced by mutations of $\beta$TEX>$\beta$-amyloid precursor protein and causes learning impairment. Moreover, $A\beta$ has a toxic effect on cultured nerve cells. To prepare AD model animals, we have examined continuous (2 weeks) infusion of $A\beta$ into the cerebral ventricle of rats. Continuous infusion of $A\beta$ induces learning impairment in water maze and passive avoidance tasks, and decreases choline acetyltransferase activity in the frontal cortex and hippocampus. Immunohistochemical analysis revealed diffuse depositions of $A\beta$ in the cerebral cortex and hippocampus around the ventricle. Furthermore, the nicotine-evoked release of acetylcholine and dopamine in the frontal cortex/hippocampus and striatum, respectively, is decreased in the $A\beta$-infused group. Perfusion of nicotine (50 $\mu\textrm{M}$) reduced the amplitude of electrically evoked population spikes in the CA1 pyramidal cells of the control group, but not in those of the $A\beta$-infused group, suggesting the impairment of nicotinic signaling in the $A\beta$-infused group. In fact, Kd, but not Bmax, values for ［$^3H$］ cytisine binding in the hippocampus significantly increased in the $A\beta$-infused rats. suggesting the decrease in affinity of nicotinic acetylcholine receptors. Long-term potentiation (LTP) induced by tetanic stimulations in CA1 pyramidal cells, which is thought to be an essential mechanism underlying learning and memory, was readily observed in the control group, whereas it was impaired in the $A\beta$-infused group. Taken together, these results suggest that $A\beta$ infusion impairs the signal transduction mechanisms via nicotinic acetylcholine receptors. This dysfunction may be responsible, at least in part, for the impairment of LTP induction and may lead to learning and memory impairment. We also found the reduction of glutathione- and Mn-superoxide dismutase-like immunoreactivity in the brains of $A\beta$-infused rats. Administration of antioxidants or nootropics alleviated learning and memory impairment induced by $A\beta$ infusion. We believe that investigation of currently available transgenic and non-transgenic animal models for AD will help to clarify the pathogenic mechanisms and allow assessment of new therapeutic strategies.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.245-249
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• 1989

The effects of varying concentrations and durations of butachlor [N-(bytoxymety 1,)-2-chlor -2, 6-diethy lacetanilide treatment on oat(Avena sativa L.) root cell division and protein synthesis were studied. The highest concentration ($1{\times}10^{-3}M$) of butachlor caused the significant inhibition of cell division after 18hrs treatment. After 18hrs treatment, 59% and 82% inhibition of cell division occurred at $1{\times}10^{-4}M$ and $1{\times}10^{-3}M$, respectively, while 9% inhibition of cell division did at $1{\times}10^{-6}M$ concentration at the same exposure period. To investigate protein synthesis, the oats were treated for 18 and 24hrs with concentrations ranging from $1{\times}10^{-6}M$ to $1{\times}10^{-3}M$ butachlor. After 18hrs, butachlor treatment of oat with $1{\times}10^{-4}M$ inhibitited 23% protein synthesis, and butachlor treatment with $1{\times}10^{-4}M$ caused 34% inhibition after 24hrs. With SDS-PAGE of proteins extracted from oat root tips, butachlor usually inhibited the 16, 18, 30, 43 and 43.5 kD polypeptide, and proteins of root tips are made up of subunits below 100 kD polypeptide.

• Journal of Life Science
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• v.22 no.11
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• pp.1500-1506
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• 2012

Transforming growth factor (TGF)-${\beta}$-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues, especially in liver, in vivo. To investigate which gene expressions are critical for TGF-${\beta}$-induced apoptosis in hepatocytes, gene expression profiling experiments were performed with TGF-${\beta}$-treated and non-treated mouse hepatocytes AML12 cells. Findings showed that serum and glucocorticoid-inducible protein kinase1 (SGK1) expression is markedly downregulated during TGF-${\beta}$-induced apoptosis. Findings confirmed that expression of SGK1 protein, as well as mRNA, is also markedly decreased with TGF-${\beta}$ treatment. Infection of adenoviral vector encoding constitutively active SGK1 (CA-SGK1), but not kinase dead SGK1 (KD-SGK1), attenuated TGF-${\beta}$-induced apoptosis. All of these results suggest that downregulation of SGK1 expression is critical for TGF-${\beta}$-induced apoptosis in AML12 cells.

• Clinical and Experimental Pediatrics
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• v.59 no.4
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• pp.174-177
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• 2016

Purpose: There are no specific tests for diagnosing Kawasaki disease (KD). Additional diagnostic criteria are needed to prevent the delayed diagnosis of incomplete Kawasaki disease (IKD). This study compared the frequency of coronary artery lesions (CALs) in IKD patients with and without anterior uveitis (AU) and elucidated whether the finding of AU supported the diagnosis of IKD. Methods: This study enrolled patients diagnosed with IKD at The Catholic University of Korea, Uijeongbu St. Mary's Hospital from January 2010 to December 2014. The patients were divided into 2 groups: group 1 included patients with IKD having AU; and group 2 included patients with IKD without AU. We analyzed the demographic and clinical data (age, gender, duration of fever, and the number of diagnostic criteria), laboratory results, and echocardiographic findings. Results: Of 111 patients with IKD, 41 had uveitis (36.98%, group 1) and 70 did not (63.02%, group 2). Patients in group 1 had received a diagnosis and treatment earlier, and had fewer CALs (3 of 41, 1.7%) than those in group 2 (20 of 70, 28.5%) (P=0.008). All 3 patients with CALs in group 1 had coronary dilatation, while patients with CALs in group 2 had CALs ranging from coronary dilatation to giant aneurysm. Conclusion: The diagnosis of IKD is challenging but can be supported by the presence of features such as AU. Group 1 had a lower risk of coronary artery disease than group 2. Therefore, the presence of AU is helpful in the early diagnosis and treatment of IKD and can be used as an additional diagnostic tool.