• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.18-24
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• 2002

The present study was performed to investigate the excellent microbial anticaries substance, aminoglycoside antibiotic, which is more effective than chlorhexidine for the treatment of dental caries. The aminoglycoside antibiotic against Streptococcus mutans JC-2 from a novel alkaliphilic Bacillus alkalophilshaggy JY-827 exhibited no significant difference at the treatment concentration of $2.5{\times}10^{-7}M$, however, it inhibited the activity of the Streptococcus mutans glucosyltransferase by 70.2% and 99.8% at the concentrations of $2.5{\times}10^{-7}$M\;and\;2.5{\times}10^{-6}M$, respectively. Lineweaver-Burk plot of the inhibitory aminoglycoside antibiotic showed competitive inhibition, with $K_i$ value of $6.4{\times}10^{-6}$ M. The aminoglycoside antibiotic did not show any cytotoxicity against human gingival cells. To evaluate the industrial applicability of the aminoglycoside antibiotic, a toothpaste containing this substance was prepared and tested on the extracted human teeth. The inhibitory rate of tooth calcification and calcium ion elution by the aminoglycoside antibiotic were 50% and 2.5 times, respectively. These results suggested that the aminoglycoside antibiotic from Bacillus alkalophilshaggy JY-827 is an effective agent against dental caries.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.590-594
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• 2011

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

• Bulletin of the Korean Chemical Society
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• v.18 no.5
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• pp.515-519
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• 1997

In a competitive enzyme immunoassay, the performance was tested with different analyte-enzyme conjugates (signal generators) in their binding constants to antibody. Analyte (progesterone)-enzyme (glucose oxidase; GO) conjugates were chemically synthesized and purified by using a gel column with an immobilized antibody to progesterone. In an elution range from the column, four peaks were detected by measuring total enzyme activities. Results from further analysis indicated that the first peak contained mainly unreacted GO while the next three peaks conjugated GO with progesterone. These three conjugate preparations were compared in dose-response curves along with the unpurified mixture. The purified conjugates showed higher detection capabilities than did the mixture. Especially, the preparation in the second peak next to the free GO peak improved the detection limit five times. This performance was comparable to that of a progesterone-horseradish peroxidase conjugate that has been identified to have one progesterone ligand.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2201-2206
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• 2010

To improve the separation property and stability of metal chelate Cu(II) column, three new kinds of multidentate aminocarboxy silica columns with cation-exchange properties were synthesized using glutamic acid (Glu), glutamic acidbromoacetic acid (Glu-BAA), glutamic acid-bromosuccinic acid (Glu-BSUA) as ligands and silica gel as matrix. The standard proteins were separated with prepared chromatographic columns. The stationary phases exhibited the metal chelate property after fixing copper ion (II) on the synthesized multidentate ligand silica columns. The binding capacity of immobilized metal ion was related with the dentate number of multidentate ligands. Chromatographic behavior of proteins and the leakage of immobilized metal ion on multidentate chelate Cu(II) columns were affected by the dentate number of multidentate ligands and competitive elution system directly. The results showed that quinquedentate Glu-BSUA-Cu(II) column exhibited better chromatographic property and stability as compared with tridentate Glu-Cu(II) column, tetradentate Glu-BAA-Cu(II) column and commonly used IDA-Cu(II) column.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.759-765
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• 2004

The NCS inhibited the activity of glucosyltransferase which was produced by Streptococcus mutans JC-2, and the rate of inhibition at $100\muM<$ and $200\muM$ were 74.0% and 99.8%, respectively. It was stable in alkali condition, but unstable in acid condition. It was also stable up to $80^{\circ}C$. The kinetic study of the inhibition by NCS was carried out by Lineweaver-Burk plot and Dixon plot. It was non-competitive inhibition, determined by the two plots and $K_i$ and $K_i$ values were $15\muM$ and $19.3\muM$ respectively. The NCS did not show cytotoxicity against human gingival cells at $K_i$ ($15\muM$, $150\muM$, $1,500\mu$ M) concentrations. It had less cytotoxicity than chlohexidin, which has usually been used as the agent of anticaries. To evaluate the industrial applicability of the NCS, human pluck tooth was used. The inhibitory rates of tooth calcification and calcium ion elution by the NCS were 41 % and 2.5 times, respectively. These results suggested that NCS from Bacillus sp. S-1013 is an efficient anticaries agent.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.524-530
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• 2006

Two protease inhibitors of 67 and 18 kDa, respectively, were purified from the eggs of glass fish, Liparis tanakai, by affinity chromatography and electro-elution method. The high molecular weight (HMW) protein was purified with a specific inhibitory activity, yield, and purity of 18.46 U/mg, 0.07%, and 131.86 fold, respectively, and was further characterized: Optimal temperature and pH for inhibitory activity of the HMW glassfish egg protease inhibitor were $40^{\circ}C$ and pH 6, respectively, and it was stable between $5^{\circ}C\;and\;50^{\circ}C$ in the pH range of 5-6 with maximal stability at pH 6. It was shown to be a competitive inhibitor against papain with an inhibition constant $(K_i)$ of 97.02 nM. Moreover, the 67 kDa protein inhibited cathepsin, a cysteine protease, more effectively than did an egg-white protease inhibitor. The HMW glassfish egg protease inhibitor was classified as a member of the family III (kininogen).

• KSBB Journal
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• v.21 no.3
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• pp.224-229
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• 2006

FEMLAB is a powerful interactive environment for modeling, solving all kinds of scientific and engineering problems based on partial differential equations(PDEs). Separation process of chiral compound in HPLC columns was simulated by FEMLAB. To study change of elution profile with isotherm models, non-competitive and competitive Langmuir adsorption isotherm were adopted. Separated material was (R, S)-ibuprofen [(R, S)-2-(4-isobutyl phenyl) propionic acid], an anti-inflammatory agent, which retain the pharmacological activity in the (S)-(+)-enantiomer. Sample concentrations were changed from 0.5 mg/ml to 2.0 mg/ml at a flow rate of 1 ml/min and flow rate varied from 1 ml/min to 3 ml/min at an ibuprofen concentration of 2.0 mg/ml and $20{\mu}l$ of injection volume. Simulated results were well fitted with experimental data.