• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.153-158
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• 1998

Effects of cyclic (c) AMP and G-protein related reagents (3-isobutyl-l-methyxanthine (IBMX), Forskolin (FSK), cholera toxin (CTX), and pertussis toxin (PTX≫ on estradiol-17$\beta$ induced vitellogenin (VTG) induction were examined in primary hepatocyte cultures in rainbow trout Oncorhynchus mykiss. The addition of IBMX, FSK, or CTX to the incubation medium markedly increased VTG production, while PTX was not effective in stimulating the production. It is well known that cAMP regulates phosphorylation and dephosphorylation through mediation of protein kinase A. These results suggest that VTG production is highly dependent on cAMP state in hepatocytes because of its highly phosphorylated nature.

• Journal of Plant Biology
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• v.37 no.4
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• pp.429-434
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• 1994

식물 호르몬의 하나인 앱시스산이 식물의 기공을 닫게 하는 과정 중에 phospholipase C가 활성화되어 inositol 1,4,5-trisphosphate(P3)의 양이 증가함이 보고되었다 (Cot and Crain. 1994). 그러나 아직까지 공변세포에서 phospholipase C의 활성을 조절하는 G-단백질에 대한 보고는 없었다. 그러므로 앱시스산에 의한 기공닫힘과정에 G-단백질이 수반되는지를 조사하고자, G-단백질 활성의 저해제인 pertussis toxin과 촉진제인 cholera toxin을 처리하여 보았다. 닭의장풀(Commelina communis L.)의 잎 뒷면으로부터 얻은 온전한 표피층과 잠두(Vicia faba L)의 잎을 부분 분해하여 공변세포만을 남긴 표피층에 pertussis toxin을 처리하였을 때, 앱시스산에 의한 기공닫힘이 부분적으로 억제됨을 관찰하였다. 그러나 cholera toxin의 경우는 아무런 영향이 없었다. 공변세포만을 지닌 표피층에 pertussis toxin을 전처리한 후 앱시스산을 가했을 때, 앱시스산에 의한 IP3 양의 증가 양상이 억제됨을 확인하였다. 이러한 결과들로부터 앱시스산에 의한 기공닫힘과정에는 pertussis toxin-sensitive, phospholipase C-linked G-protein이 관여하고 있음을 알 수 있었다.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.152-153
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.13-15
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• 2005

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.133-142
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• 2018

Objectives: The pathogenic Vibrios genus denotes halophilic bacteria that are distributed in aquatic environments, including both sea and freshwater. Vibrio cholerae, Vibrio vulnificus, and Vibrio parahaemolyticus are the most important species since they can be potent human pathogens and leading causes of septicemia, wound infections, and seafood borne gastroenteritis. The recent emergence of a potential pandemic clone, V. cholera serotype O1 and the cholera outbreak in South Korea in 2016 indicates the importance of consistent surveillance of pathogenic Vibrio genus within coastal areas. Methods: The present study was undertaken to determine where and how vibrios live in the aquatic environment adjacent to coastal areas of South Korea. For this survey, a total of 838 samples were obtained at 35 different sites in South Korean coastal areas during the period from January 2016 to December 2016. Pathogenic vibrios was determined using the real-time PCR method, and its clones were isolated using three selective plating media. We also monitored changes in seawater and atmospheric temperature, salinity, turbidity, and hydrogen ion concentration at the collection points. Results: The total isolation rates of V. vulnificus, V. cholera (non-pathogenic, non-O1, non-O139 serogroups), and V. parahaemolyticus from seawater specimens in 2016 were 14.2, 13.48, and 67.06%, respectively. Conclusions: The isolation rates of pathogenic vibrios genus showed a positive correlation with temperature of seawater and atmosphere but were negatively correlated with salinity and turbidity.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.552-559
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• 2003

The FimH subunit of type 1-fimbriated Escherichiu coli (E. coli) has been determined as a major cause for urinary tract infections. Thus, to produce a possible vaccine antigen against urinary tract infections, the fimIH gene was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. A fusion protein, based on fusing adhesin to the cholera toxin subunit A2B (CTXA2B), was induced with 0.01 mM isopropyl-${\beta}-D-thiogalactoside$ (IPTG) for 4 h at $37^{\circ}C$ to yield a soluble fusion protein. The fusion protein was then purified by affinity chromatography. The expressed fusion protein was confirmed by SDS-PAGE and Western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was also analyzed. The orderly-assembled fusion protein was confirmed by a modified $G_{Ml}-ganglioside$ ELISA, using antibodies to adhesin. The results indicated that the purified fusion protein was an adhesin/CTXA2B protein containing E. coli adhesin and the $G_{Ml}-ganglioside$ binding activity of CTXB. Accordingly, this adhesin/CTXA2B protein may be a potential antigen for oral immunization against uropathogenic E. coli.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.56-62
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• 2000

The hpa gene genetically linked to the ctxa2b gene was cloned into the pTED expression vector, and the constructed pTEDhpa/ctxa2b was transformed into Excherichia coli. The fusion protein, the adhesin fused to the cholera toxin subunit A2B (CTXA2B) subunit, was expressed to high levels as inclusion bodies in E. coli. The expressed protein was partially purified by washing the inclusion bodies with working solution containing 8M Urea and 0.1M DTT. Refolding of denatured fusion protein was carried out in the presence of glutathione redox buffer. The refolded fusion protein was purified by size exclusion chromatography. The expressed fusion protein was verified by SDS-PAGE, western blotting with antibodies to both antigenic components of adhesin and cholera toxin subunit B (CTXB), and its N-terminal amino acid sequence was analyzed. The orderly assembled fusion protein was confirmed by modified Gm1-ganglioside ELISA with Abs to adhesin. The results indicate that the purified fusion protein is an Adhesin/CTXA2B protein containing the H. pylori adhesin and $G_{m1}4-ganglioside binding activity of CTXB and the expressed fusion protein in E. coli could be easily purified by the refolding process, Its molecular weight was 168kDa as estimated by size exclusion chromatography. The Adhesin/CTXA2B protein may be used as a candidate antigen for oral immunization against H. pylori.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.268-274
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• 2009

Porphyromonas gingivalis, the gram-negative anaerobic oral bacterium, initiates periodontal disease by binding to saliva-coated oral surface. The cholera toxin B subunit (CTB) genetically linked to FimA1 (1-200 aa) or FimA2 (201-337 aa) of the P. gingivalis fimbrial antigen were introduced into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated transformation method. The integration of CTB-FimA1 or CTB-FimA2 fusion genes were confirmed in the chromosome of transformed leaves by genomic DNA PCR amplification method. Synthesis and assembly of the CTB-FimA fusion proteins into oligomeric structures with pentamer size was detected in transformed tuber extracts by immunoblot analysis. The binding activities of CTB-FimA fusion proteins to intestinal epithelial cell membrane receptors were confirmed by GM1-ganglioside enzyme-linked immunosorbent assay (GM1-ELISA). The ELISA showed that the expression levels of the CTB-FimA1 or CTB-FimA2 fusion proteins were 0.0019, 0.002% of the total soluble protein in transgenic tuber tissues, respectively The synthesis of CTB-FimA monomers and their assembly into biologically active oligomers in transformed potato tuber tissues demonstrates the feasibility of using edible plants for the production of enterocyte targeted fimbrial antigens that could elicit mucosal immune responses.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.435-440
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• 1990

Ten pigs infected with Aujeszky's disease virus (ADY) or hog cholera virus(HCV) were tested for the detection of virus antigens in frozens or paraffin-embedded sections by avidin-biotin-peroxidase complex(ABC) method. Tonsils, spleens, cerebra and buffy coats were examined for the immunohistochemical test. Where ADV antigen was detected by ABC, a dark brown deposit occurred in both the nucleus and the cytoplasm of lymphocytes and macrophages, however, HCV antigen was demonstrated in the cytoplasm of the infected cells. ADV-positive cells were most frequently detected in tonsils and cerebra, whereas, HCV -positive cells were frequently observed in spleens. And buffy coat were also good for both virus detection. The results suggested that ABC method is considered as an excellent and reliable tool for confirmative diagnosis of these viral diseases.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.582-586
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• 2005

The present study was designed to characterize the possible roles of spinally located cholera toxin (CTX)- and pertussis toxin (PTX)-sensitive G-proteins in pro- inflammatory cy tokine induced pain behaviors. Intrathecal injection of tumor necrosis factor-a (TNF-${\alpha}$; 100 pg), interleukin-1${\beta}$ (IL-1${\beta}$ 100 pg) and interferon-${\gamma}$ (INF-${\gamma}$; 100 pg) showed pain behavior. Intrathecal pretreatment with CTX (0.05, 0.1 and 0.5 mg) attenuated pain behavior induced by TNF-${\alpha}$ and INF-${\gamma}$ administered intrathecally. But intrathecal pretreatment with CTX (0.05, 0.1 and 0.5${\mu}g$) did not attenuate pain behavior induced by IL-1${\beta}$. On the other hand, intrathecal pretreatment with PTX further increased the pain behavior induced by TNF-${\alpha}$ and IL-1${\beta}$ administered intrathecally, especially at the dose of 0.5 ${\mu}g$. But intrathecal pretreatment with PTX did not affect pain behavior induced by INF-${\gamma}$. Our results suggest that, at the spinal cord level, CTX- and PTX-sensitive G-proteins appear to play important roles in modulating pain behavior induced by pro-inflammatory cytokines administered spinally. Furthermore, TNF-${\alpha}$, IL-1${\beta}$ arid INF-${\gamma}$ administered spinally appear to produce pain behavior by different mechanisms.