• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.892-898
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• 2005

A long, bis(monodentate), linking Schiff-base ligand L (py-CH=N-$C_6H_4$-N=CH-py) was prepared from 1,4-phenylenediamine and 3-pyridinecarboxaldehyde by the Schiff-base condensation. Ligand L has two terminal pyridyl groups capable of coordinating to metals through their nitrogen atoms. In contrast, the same reaction between 1,2-phenylenediamine and 3-pyridinecarboxaldehyde produced a mixture of imidazol isomers (2-pyridin-3-yl-1H-benzoimidazole), which are connected to one another by the N-H…N hydrogen bonding to form a tetramer. From Zn($NO_3)_2{\cdot}6H_2O$ and ligand L under various conditions, one discrete molecule, trans- [Zn($H_2O)_4L_2]{\cdot}(NO_3)_2{\cdot}(MeOH)_2$, and two 1-D zinc polymers, [Zn$(NO_3)(H_2O)_2(L)]{\cdot}(NO_3){\cdot}(H_2O)_2$ and [Zn(L) (OBC)($H_2O$)], were prepared. In ligand L, the N$\ldots$N separation between the terminal pyridyl groups is 13.994 $\AA$, with their nitrogen atoms at the meta positions (3,3’) in a trans manner. The corresponding N$\ldots$N separations in its compounds range from 13.853 to 14.754 $\AA$.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.606-612
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• 1989

A New lectin from baby clam, Tapes japonica, was isolated and purified through the following procedures; acetone powder, 0.15M NaCl extraction, ammonium sulfate fractionation, N-acetyl-D-galactosamine-agarose affinity column, and ion exchange Mono Q of FPLC. This lectin nonspecifically agglutinated human erythrocytes but didn't agglutinate mouse and rabbit erythrocytes. And the lectin neither stimulated human lymphocytes nor agglutinated Sarcoma 180 cells. On polyacrylamide gel electrophoresis, the lectin migrated as a major single band indicating homogeneous. A molecular weight was estimated to be about 131,000 daltons by Biogel P-300 and 125,000 daltons by SDS-PAGE without ${\beta}-mercaptoethanol$. This lectin is supposed to be a tetramer composed of heterogeneous subunits, about 30,000 and 33,000 daltons. Baby clam lectin was inhibited by EDTA and recovered agglutinating activity by $Ca^{++}\;and\;Mn^{++}$. This lectin is revealed as glycoprotein that contained about 4.2% neutral sugar.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.484-492
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• 2022

Lichenase is an enzyme mainly implicated in the degradation of polysaccharides in the cell walls of grains. Emerging evidence shows that a highly efficient expression of a thermostable recombinant lichenase holds considerable promise for application in the beer-brewing and animal feed industries. Herein, we cloned a lichenase gene (CelA203) from Bacillus subtilis B110 and expressed it in E. coli. This gene contains an ORF of 729 bp, encoding a protein with 242 amino acids and a calculated molecular mass of 27.3 kDa. According to the zymogram results, purified CelA203 existed in two forms, a monomer, and a tetramer, but only the tetramer had potent enzymatic activity. CelA203 remained stable over a broad pH and temperature range and retained 40% activity at 70℃ for 1 h. The K_m and V_max of CelA203 towards barley β-glucan and lichenan were 3.98 mg/ml, 1017.17 U/mg, and 2.78 mg/ml, 198.24 U/mg, respectively. Furthermore, trisaccharide and tetrasaccharide were the main products obtained from CelA203-mediated hydrolysis of deactivated oat bran. These findings demonstrate a promising role for CelA203 in the production of oligosaccharides in animal feed and brewing industries.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.92-101
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• 2020

The cyclic Arg-Gly-Asp (cRGD) peptide is well-known as a binding molecule to the integrin α_vβ₃ receptor which is highly expressed on activated endothelial cells and new blood vessels in tumors. Although numerous results have been reported by the usage of cRGD peptide-based ligands for cancer diagnosis and therapy, the distinct mechanisms, and functions of cRGD-integrin binding to cancer cells are still being investigated. In this study, we evaluated the internalization efficacy of different types of cRGD peptides (monomer, dimer and tetramer form) in integrin α_vβ₃ overexpressing cancer cells. Western blot and flow cytometric analysis showed U87MG expresses highly integrin α_vβ₃, whereas CT-26 does not show integrin α_vβ₃ expression. Cytotoxicity assay indicated that all cRGD peptides (0-200 µM) had at least 70-80% of viability in U87MG cells. Fluorescence images showed cRGD dimer peptides have the highest cellular internalization compare to cRGD monomer and cRGD tetramer peptides. Additionally, transmission electron microscope results clearly visualized the endocytic internalization of integrin α_vβ₃ receptors and correlated with confocal microscopic results. These results support the rationale for the use of cRGD dimer peptides for imaging, diagnosis, or therapy of integrin α_vβ₃-rich glioblastoma.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.39-48
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• 1996

A storage protein(SP-2) was confirmed in haemolymph during larval-pupal-adult development of tobacco burdworm(Helicoverpa assulta Guenee), and its biochemical characteristics were investigated. The titer of SP-2 showed a peak at mature larva, decreased gradually through the late pupal stage, and became undetectable at adult period. As the results from electrophoretic mnysis, SP-2 was confirmed to be glycolipoprotein(M.W. 332kDa) relatively stable to heat( $\leq$ 68$^{\circ}C$ ). This storage protein was determined to be a tetramer composed of a single subunit with MW of 83kDa, and the isoelectric point was 5.7. The amino acid composition of the SP-2 was characterized. It has relatively high content of methionine and histidine, whereas the contents of tyrosine and phenylalanine were relatively low.

• BMB Reports
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• v.43 no.5
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• pp.325-329
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• 2010

Protein kinase CKII (CKII), a heterotetramer composed of two catalytic ($\alpha$ or $\alpha$') subunits and two regulatory ($\beta$) subunits, plays a critical role in cell proliferation and anti-apoptosis. Recently, capsaicin was shown to trigger apoptosis. Therefore, we examined the effect of capsaicin on CKII activity. Although capsaicin induced apoptotic death in HeLa cells, CKII activity was increased in the cytosolic fraction of HeLa cells after treatment. Capsaicin did not change the expression of the $CKII{\alpha}$ and $CKII{\beta}$ proteins. Capsaicin stimulated the catalytic activity of recombinant CKII tetramer, but not the $CKII{\alpha}$ subunit. Moreover, capsaicin enhanced the autophosphorylation of $CKII{\alpha}$ and $CKII{\beta}$. Taken together, our data suggest that capsaicin stimulates the phosphotransferase activity of CKII holoenzyme by interacting with the $CKII{\beta}$ subunit.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.334-340
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• 2005

Lectin is a cell-agglutinating and carbohydrate-binding protein present in many plants. The lectin of Canavalia ensiformis shoot with specific affinity for D-glucose was purified by affinity chromatography using Sephadex G-100, and some of its biochemical characterizations were studied. Lectin was purified 8.87-fold and exhibited final specific activity of 225.74 units/mg protein with a $2.3\%$ yield. SDS-PAGE analysis demonstrated that the purified shoot lectin exists as a tetramer of 102 kD, composed of two subunits with molecular weight of 29 and 22 kD. The purified lectin was observed to agglutinate rabbit blood cell. The optimal temperature for the activity of this lectin was $40^{\circ}C$, and this lectin was relatively stable to heat with the highest activity at $50{\~}60^{\circ}C$. The maximal activity was observed at pH 7.2.

• Journal of the Korean Magnetic Resonance Society
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• v.10 no.1
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• pp.38-45
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• 2006

The NMR and MS techniques were applied to identification and quantitative analysis of oligomers in a commercialized poly (trimethylene terephthalate). Oligomers in a commercialized poly (trimethylene terephthalate) were extracted via a dissolving and reprecipitation method. Analysis of the components of the extract using NMR and MS revealed that it contained mainly cyclic oligomers with degrees of polymerization of 2, 4 and 5 (dimer, tetramer and pentamer). Trimer and cyclic oligomers with degrees of polymerization of more than 6 were not found in the extract in the present study. Quantitative analysis of dimer was performed by NMR spectroscopy.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.587-592
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• 1989

A strain of alkalophilic Bacillus sp. YS-309 capable of producing large amount of $\beta$-galactosidase has been isolated from soil sample. Intracellular $\beta$-galactosidase was purified 6.9 folds by procedures including ammonium sulfate precipitation, DEAE-cellulose chromatography, gel-filtration, DEAE-Sephadex A-50 chromatography with over-all yield of 17.8%. The molecular weight of native enzyme was 205, 000 by HPLC, and SDS-polyacrylamide gel electrophoresis showed that the enzyme consisted of 4 identical subunits with a molecular weight of 56, 000.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.593-598
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• 1995

The cultural conditions of Bullera singularis were optimized for the efficient production of galactooligosaccharide (GOS), Optimum temperature was 25$\circ$C, pH was 6.0, inoculum size was over 5% (v/v), initial lactose concentration was over 5% (w/v). The GOS production increased with microbial growth. Maximum amount of 72% (w/w) GOS was obtained from the optimized medium (5% lactose and 0.75% yeast extract) in 70 hours. Seven types of GOS (3 of dimer, 2 of trimer, 1 of tetramer, and 1 of pentamer) were identified by two-dimensional TLC. A new mechanism of GOS production is proposed based on the metabolism of carbon source.