• Journal of Ginseng Research
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• v.43 no.3
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• pp.452-459
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• 2019

Background: Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B ($NF-{\kappa}B$) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated. Methods: Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for $NF-{\kappa}B$, immunofluorescence imaging for the subcellular localization of Annexin A2 and $NF-{\kappa}B$ p50 subunit, coimmunoprecipitation of Annexin A2 and $NF-{\kappa}B$ p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability. Results: Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and $NF-{\kappa}B$ p50 subunit and their nuclear colocalization, which attenuated the activation of $NF-{\kappa}B$ and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2. Conclusion: This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.

• Journal of Life Science
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• v.14 no.4
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• pp.708-715
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• 2004

The lactate dehydrogenase (EC 1.1.1.27, LDH) in liver of Lempetra japonica was purified in buffer of affinity chromatography. The liver-specific $C_4$ isozyme of Gadus macrocephalus was purified by heat treatment, affinity chromatography, and DEAE-Sephacel chromatography. The liver-specific $C_4$ isozyme was eluted in a buffer containing NAD+ and was coeluted with $B_4$isozyme in plain buffer of affinity chromagraphy. Liver-specific $C_4$ isozyme in G. macrocephalus was the most thermostable, and$B_4$isozyme was more stable than $A_4$. The LDH in the fraction of pH 7.45 purified from the liver of L. iaponica by chromatofocusing was more inhibited by pyruvate than purified LDH. The optimum pH of the LDH isozyme in the liver of L. japonica was 7.5 and that of liver-specific$C_4$ isozyme was 8.5. The LDH in liver of L. japonica made complexes more with antibody against Coreoperca herzi$A_4$ and liver-specific $C_4$ than with that against eye-specific $C_4$. Therefore, the structure of the LDH in liver of L. japonica might be similarly evolved to that of subunit A and liver-specific $C_4$ isozyme in liver tissue of G. macrocephalus. The evolution rate of subunit C is faster than that of subunit A. LDH in liver of L. japonica has not one isozyme but isozymes and it was also found out to have not only subunit A and B but also subunit C.

• BMB Reports
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• v.38 no.6
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• pp.717-724
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• 2005

The nontoxic B subunit of cholera toxin (CTB) can significantly increase the ability of proteins to induce immunological tolerance after oral administration, when it was conjugated to various proteins. Recombinant CTB offers great potential for treatment of autoimmune disease. Here we firstly investigated the feasibility of silkworm baculovirus expression vector system for the cost-effective production of CTB under the control of a strong polyhedrin promoter. Higher expression was achieved via introducing the partial non-coding and coding sequences (ATAAAT and ATGCCGAAT) of polyhedrin to the 5' end of the native CTB gene, with the maximal accumulation being approximately 54.4 mg/L of hemolymph. The silkworm bioreactor produced this protein vaccine as the glycoslated pentameric form, which retained the GM1-ganglioside binding affinity and the native antigenicity of CTB. Further studies revealed that mixing with silkworm-derived CTB increases the tolerogenic potential of insulin. In the nonconjugated form, an insulin : CTB ratio of 100 : 1 was optimal for the prominent reduction in pancreatic islet inflammation. The data presented here demonstrate that the silkworm bioreactor is an ideal production and delivery system for an oral protein vaccine designed to develop immunological tolerance against autoimmune diabetes and CTB functions as an effective mucosal adjuvant for oral tolerance induction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.991-993
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• 2012

We analyzed RNA polymerase beta subunit gene (rpoB) mutation of rifampin-resistant Mycobacteria through analysis of nucleotide sequence of rpoB DNA (351 bp) containing rifampin resistant region, $rif^r$. For this study, we collected rifampin-resistant Mycobacteria that were identified by conventional culture methods from Masan National Hospital and The Korean Institute of Tuberculosis. We performed sequencing of DNA nucleotides and analyzed rpoB gene of those rifampin-resistant Mycobacteria. From this analysis, we invcestigated diverse mutations of rpoB gene included rifampin-resistant gene, which were not reported, from those rifampin-resistant Mycobacteria.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.5
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• pp.427-436
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• 2023

Mitotic arrest deficient 2 like 2 (Mad2L2, also known as Mad2B), the human homologue of the yeast Rev7 protein, is a regulatory subunit of DNA polymerase ζ that shares high sequence homology with Mad2, the mitotic checkpoint protein. Previously, we demonstrated the involvement of Mad2B in the cisplatin-induced DNA damage response. In this study, we extend our findings to show that Mad2B is recruited to sites of DNA damage in human cancer cells in response to cisplatin treatment. We found that in undamaged cells, Mad2B exists in a complex with Polζ-Rev1 and the APC/C subunit Cdc27. Following cisplatin-induced DNA damage, we observed an increase in the recruitment of Mad2B and Cdc20 (the activators of the APC/C), to the complex. The involvement of Mad2B-Cdc20-APC/C during DNA damage has not been reported before and suggests that the APC/C is activated following cisplatin-induced DNA damage. Using an in vitro ubiquitination assay, our data confirmed Mad2B-dependent activation of APC/C in cisplatin-treated cells. Mad2B may act as an accelerator for APC/C activation during DNA damage response. Our data strongly suggest a role for Mad2B-APC/C-Cdc20 in the ubiquitination of proteins involved in the DNA damage response.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.913-915
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• 2012

RNA polymerase beta subunit gene (rpoB) mutation of rifampin-resistant Mycobacteria was analyzed using nucleotide sequence of rpoB DNA (351 bp) containing rifampin resistant region, $rif^r$. For this purpose, we collected rifampin-resistant Mycobacteria that were identified by conventional culture method from Masan National Hospital and The Korean Institute of Tuberculosis and performed analysis of nucleotide sequence of rpoB of them. We found various mutations of rpoB linked rifampin resistant gene from rifampin-resistant Mycobacteria. From this study, we identified mutations of different codons from codons that have been reported recently.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.391-398
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• 2006

$NF-{\kappa}B$ is a transcription factor involved in the innate immunity against bacterial infection and inflammation. It is also known to render cells resistant to the apoptosis caused by some anticancer drugs. Such a chemoresistance of cancer cells may be related to the activation of $NF-{\kappa}B$ transcription factor; however, the mechanism of activation is not well understood. Here, we demonstrate that a chemotherapeutic agent, etoposide, independently stimulates the $I{\kappa}B{\alpha}$ degradation pathway and PI3-kinase/Akt signaling pathway: The classical $I{\kappa}B{\alpha}$ degradation pathway leads to the nuclear translocation and DNA binding of p65 subunit through $IKK{\beta}$ kinase, whereas the PI3-kinase/Akt pathway plays a distinct role in activating this transcription factor. The PI3-kinase/Akt pathway acts on the p50 subunit of the $NF-{\kappa}B$ transcription factor and enhances the DNA binding affinity of the p50 protein. It may also explain the role of the PI3-kinase/Akt pathway in the anti-apoptotic function of $NF-{\kappa}B$ during chemoresistance of cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6911-6917
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• 2014

Background: Hepatocellular carcinoma is a complex and heterogeneous tumor with poor prognosis due to frequent intrahepatic spread and extrahepatic metastasis. The molecular mechanisms underlying HCC pathogenesis still remain obscure. Objectives: We aimed to investigate the abundance and the DNA binding activity of nuclear factor kappa B/p65 subunit in peripheral blood mononuclear cells from patients with HCC and to assess its prognostic significance and association with hypoxia inducible factor one alpha (HIF-$1{\alpha}$) in blood. Subjects and methods: This study was carried out on 40 patients classified equally into liver cirrhosis (group I) and HCC (group II), in addition to 20 healthy volunteers (group III). All groups were subjected to measurement of NF-${\kappa}B$/P65 subunit expression levels by real time-PCR, and DNA binding activity was evaluated by transcription factor binding immunoassay. Serum HIF-$1{\alpha}$ levels were estimated by enzyme-linked immunosorbent assay (ELISA). Significant increase of both the expression level and DNA binding activity of NF-${\kappa}B$/P65 subunit together with serum HIF-1 alpha levels was noted in HCC patients compared to liver cirrhosis and control subjects, with significant positive correlation with parameters for bad prognosis of HCC. In conclusion, NF-${\kappa}B$ signaling is activated in HCC and associated with disease prognosis and with high circulating levels of HIF-1 alpha.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.707-711
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• 1998

The (Na,K)ATPase is responsible for generating the ionic gradients and membrane potentials by the exchange of intracellular $Na^+$ for $K^+$. It has been recentl y shown that (Na,K)ATPase is involved in the exocytic pathway of basic fibroblast growth factor (bFGF), although it is not known that bFGF is secreted to the outside of cell through direct interaction with (Na,K) ATPase. To understand the role for (Na,K)ATPase in the secretary pathway of bFGF, we have sought to identify the cytoplasmic domains of the alpha1 isoform of (Na,K)ATPase interacting with bFGF by yeast two-hybrid system. We have also investigated the interaction between the alpha2 isoform of (Na,K)ATPase and bFGF to find out whether the interaction is isoform-specific. We found that none of the cytoplasmic domains of (Na,K)ATPase isoforms interacted with bFGF. The result suggests that the interaction between bFGF and (Na,K)ATPase might be indirect, thus requiring other proteins which are involved in the formation of protein complexes for the interaction, although we cannot exclude the possibility that the interaction requires the element of the whole alpha subunit structure that was not present in the isolated alpha subunit cytoplasmic domains.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.179-184
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• 2004

The FimH subunit of type 1-fimbriated Escherichia coli has been determined as a major cause for urinary tract infections. In our previous study, the Adhesin/CTXA2B was expressed as soluble recombinant chimaeric protein derived from the uropathogenic Escherichia coli adhesin genetically coupled to cholera toxin A2B (CTXA2B) subunit in Escherichia coli. Since it is very important to optimize IPTG concentration and culture temperature to maximize cell growth and productivity, These optimal culture factors were determined to increase the productivity of the expressed Adhesin/CTXA2B chimaeric protein in Escherichia coli TB1 carrying pMALfimH/ctxa2b. Our data demonstrate that optimal concentration of IPTG for increased production of chimaeric protein was 0.5 mM. Additionally, culture time was 10 hours and temperature, 37${\circ}C$.