• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.685-690
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• 2007

The deoxysugar biosynthetic gene cluster of Sch 47554/Sch 47555 was cloned from Streptomyces sp. SCC-2136. One of the ORFs, schS6, appeared to encode glucose-1-phosphate thymidylyltransferase, which converts dTTP and glucose-1-phosphate to TDP-D-glucose and pyrophosphate. The dTDP-D-glucose is a key metabolite in prokaryotics as a precursor for a large number of modified deoxysugars, and these deoxysugars are a maj or part of various antibiotics, ranging from glycosides to macrolides. SchS6 was expressed in E. coli vector pSCHS6 and the expressed protein was purified to apparent homogeneity by ammonium sulfate precipitation and Ni-NTA affinity column chromatography. The specific activity of the purified enzyme increased 4.7-fold with 17.5% recovery. It migrated as a single band on SDS-PAGE with an apparent molecular mass of 56kDa. The purified protein showed glucose-1-phosphate thymidylyltransferase activity, catalyzing a reversible bimolecular group transfer reaction. In the forward reaction, the highest activity was obtained with combination of dTTP and ${\alpha}-D-glucose-1-phosphate$, and only 12% of that activity was obtained with the substrates $UTP/{\alpha}-D-glucose-1-phosphate$. In the opposite direction, the purified protein was highly specific for dTDP-D-glucose and pyrophosphate.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.446-446
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• 2000

Specific polyclonal and/or monoclonal antibodies (MAbs) to immunoglobulins (Igs) and their subunits have proved to be valuable tools in immunological research and in immunological assays. In this study, we developed and characterized MAbs against flounder serum Igs. To obtain the pure flounder serum Igs, mouse IgG (mIgG) was immunized to flounder. Flounder Igs were purified by using mIgG-agarose affinity column chromatography. The structure of purified flounder Ig was observed, on denatured SDS-PAGE, to be composed of two heavy chains (77 and 72 kd) and two light chains (28 and 26 kd). MAbs were produced by fusion of myeloma cells (SP2/0) with Balb/c mouse spleen cells previously primed with the flounder Igs. Finally, three hybridoma clones, FIM 511, FIM 519 and FIM 562 were established to recognize both 2 heavy chains, 26 kd of light chain and 28 kd of light chain, respectively. On the other hand, the flounder immune sera collected on the weekly basis were tested on ELISA and immunoblot analysis whether boosting effect is present in flounder humoral immune system. As a result, the secondary immune response in flounder was ascertained on ELISA, but not on immunoblot analysis. Further, we observed an alteration of serum protein levels following immunization. Our MAbs and basic information on flounder humoral immune system obtained in this study will be helpful to control and monitor the efficiency of fish vaccines and therapeutic process of flounder diseases.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1756-1763
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• 2010

Pasteurella multocida serogroup D strain, which produces P. multocida toxin (PMT), is a widespread and harmful pathogen of respiratory diseases such as pneumonia and progressive atrophic rhinitis (PAR) in swine. Vaccination has been considered the most desirable and effective approach for controlling the diseases caused by toxigenic P. multocida. To investigate the antigenicity and immunogenicity of partial fragments of recombinant PMT, recombinant proteins of the N-terminal (PMT-A), middle (PMT-B), C-terminal (PMT-C), and middle-C-terminal (PMT2.3) regions of PMT were successfully produced in an Escherichia coli expression system. The molecular masses of PMT-A, PMT-B, PMT-C, and PMT2.3 were ca. 53, 55, 35, and 84 kDa, respectively, purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity column chromatography. All the recombinant proteins except for PMT-A showed immune responses to antisera obtained from a swine showing symptoms of PAR. Moreover, high titers of PMT-specific antibodies were raised from mice immunized with each of the recombinant proteins; however, the immunoreactivities of the antibodies to authentic PMT and heat-inactivated whole bacteria were different, respectively. In the protection study, the highest protection against homologous challenge was shown in the case of PMT2.3; relatively poor protections occurred for the other PMT fragments.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.41-41
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• 2003

Small conductance calcium-activated potassium channels (or SKCa channels) are potassium selective, voltage-independent, and activated by intracellular calcium concentration. These channels play important roles in excitable cells such as neuron in the central nervous system (Vergara et al., 1998). The activity of SKCa channels underlies the slow afterhyperpolarization that inhibits neuronal cell firing (Hille, 1991; Vergara et al.,1998). Until now, N-terminal region of rSK2 isn't characterized. To study the role of N-terminus, we constructed the N-terminal deletion mutant and characterized by electrophysiological means. Interestingly, N-terminal deletion mutant be trafficked to membrane couldn't evoke any ionic currents. Thus, N-terminal region has a role in functional rSK2 channel formation. To elucidate the function of N-terminal region, (His)6-conjugated protein was purified and filtrated by affinity column chromatography. Surprisingly, N-terminal region was shown in tetramer size that was supported by cross-linking result. Thus, we predicted that N-terminal region might be involved in the tetramerization of rSK2.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.420-426
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• 1993

To effectively purify of IL-1 inhibitor from human febrile urine, we have established monoclonal antibody that reacts with human recombinant interleukin l$\beta$(IL-1$\beta$). The antibody, designated ON-1, was highly specific to IL-1$\beta$ and no cross-reaction with other cytokines(IL-l$\alpha$ and IL-4) was observed. As the results of ELISA inhibition assay and Western blotting method, it was further identified that ON-1 had high binding specificity with IL-1$\beta$. IL-1 receptor binding material from febrile patient urine was effectively purified with affinity column chromatography which conjugated with ON-1. This urinary material inhibited the thymocyte proliferation in a dosedependent manner. IL-l$\beta$ induced thymocyte proliferation activity was inhibited to 67.3% at 6 $\mu\textrm{g}$ of the purified urinary material. The result may suggest that this urinary material the purified urinary material. The result may suggest that this urinary material will have antagonic effect on IL-1 action mechanism and act IL-l$\beta$ inhibitor.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.43-50
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• 1998

Induction and purification of the GroEL homolog from Streptococcus pneumolliae were characterized. The stress conditions were determined by temperature, ethanol, NaCI, $H_2O_2$ methyl methanesulfonate, and ethyl methanesulfonate. And stress induced proteins were analyzed using [$^{35}S$]-methionine labeling method. Heat shock induced the synthesis of a set of about 3 heat shock proteins (hsps) (65, 73, and 84-kDa). Of those 3 hsps, a 65 kDa protein, hsp65, was purified by DEAE-Sephacel and ATP-agarose column chromatography, and used for antibody preparation. Immunoblot analysis employing antisera raised against pneumococcus hsp65 demonstrated cross-reactivity with a 60 kDa protein in Eschericha coli. Also cross reaction of the purified p65 with anti-Escherichia coli GroEL monoclonal antibody demonstrated that pneumococcal hsp65 is the GroEL homolog.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1327-1338
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• 2013

The humanized anti-hepatocyte growth factor (HGF) monoclonal antibody (mAb) YYB-101 is a promising therapeutic candidate for treating various cancers. In this study, we developed a bioprocess for large-scale production of YYB-101 and evaluated its therapeutic potential for tumor treatment using a xenograft mouse model. By screening diverse chemically defined basal media formulations and by assessing the effects of various feed supplements and feeding schedules on cell growth and antibody production, we established an optimal medium and feeding method to produce 757 mg/l of YYB-101 in flask cultures, representing a 7.5-fold increase in titer compared with that obtained under non-optimized conditions. The optimal dissolved oxygen concentration for antibody production was 70% $pO_2$. A pH shift from 7.2 to 7.0, rather than controlled pH of either 7.0 or 7.2, resulted in productivity improvement in 5 L and 200 L bioreactors, yielding 737 and 830 mg/ml of YYB-101, respectively. The YYB-101 mAb highly purified by affinity chromatography using a Protein A column and two-step ion exchange chromatography effectively neutralized HGF in a cell-based assay and showed potent tumor suppression activity in a mouse xenograft model established with human glioblastoma cells.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.6
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• pp.340-346
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• 2002

The purpose of the present study was to examine the efficacy and mechanism of the PAB (para-amino benzamidine) affinity column chromatography, Viresolve NFP virus filtration, pasteurization (60$\^{C}$ heat treatment for 10 h), and lyophilization steps employed in the manufacture of urokinase from human urine as regards the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and subjected to scale-down processes mimicking the manufacture of urokinase Samples were collected at each step, immediately titrated using a 50% tissue culture infectious dose (TCID$\_$50/), and the virus reduction factors evaluated. PAB chromatography was found to be an effective step for removing HAV with a log reduction factor of 3.24. HAV infectivity was rarely detected in the urokinase fraction, while most of the HAV infectivity was recovered in the unbound and wash fractions. HAV was completely removed during the Viresolve NFP filtration with a log reduction factor of $\geq$ 4.60. Pasteurization was also found to be an effective step in inactivating HAV where the titers were reduced from an initial titer of 7.18 log$\_$10/ TCID$\_$50/ to undetectable levels within 10 h of treatment. The log reduction factor achieved during pasteurization was $\geq$ 4.76. Lyophilization revealed the lowest efficacy for inactivating HAV with a log reduction factor of 1.48. The cumulative log reduction factor was $\geq$ 14.08. Accordingly, these results indicate that the production process for urokinase exhibited a sufficient HAV reducing capacity to achieve a high margin of virus safety.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.928-934
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• 2005

ATF2 is a cellular transcription factor which belongs to the CREB/ATF class and it is leucine zipper protein which generally binds to DNA as dimers. This paper presents the procedure for subcloning the ATF2 gene and the results of experiment used the expressed ATF2. The pET expression vector was used since it produced 6xHis fusion protein for easy purification using affinity column. The Nickel chelating chromatography was used for Purifying the expressed ATE2 from E- codi BL2l. Subsequen시y In vitro binding pull-down assay showed the binding specificity of ATF2 with AP-1 family factors such as BATF, c-Fos, c-Jun and ATF2 itselgf. ATF2 forms homodimer as well as strong heterodimer with BATF. It also forms stable dimer with c-Jun but barely binds with c-Fos.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.110-117
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• 1987

Polyphenol oxidase in Prunus salicina(Red) was extracted, some properties and its partially purification were investigated as follows; Polyphenol oxidase was purified about 15 folds after ammonium sulfate saturation and about 64 folds after Sephadex G-100 column chromatography. Polyphenol oxidase showed optimum pH for activity at 6.5 and optimum temperature at at $35^{\circ}C$ and high affinity to catechol in o-diphenol compounds. Thermal stability were about 85% and 75% of initial polyphenol oxidase activity remained after heating at $50^{\circ}C$ for 5 minutes and 30 minutes respectively. The Michaelis constant of the enzyme was 2.58mM. L-cysteine, glutathione, ascorbic acid and potassium cyanide appeared to be most effective inhibitors. EDTA showed a slight inhibition.