• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.1028-1032
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• 1999

Alpha toxin of S aureus has cytolytic activity respectively. This antigen has been received the most attention since it is a major virulence factor in pathogenesis of staphylococcal mastitis. Thus, alpha toxin has been focused as potential candidate of vaccine to minimize mastitis in cows. The purpose of this study was to develop a simple, efficient production and purification methods of sufficient amount of alpha toxin antigen from S aureus. Alpha toxin production measured by hemolytic activity was the highest at 18 hrs postinoculation in yeast extract culture medium supplemented with thiamine, nicotinic acid and casamino acid. Alpha toxin was purified by ammonium sulfate precipitation (65%) and ultrafiltration. Molecular weight of the toxin was 33 kDa in the analysis with SDS-PAGE. Conclusionally, when alpha toxin was included in the vaccine, the optimal harvest time of alpha toxin was at 18 hrs after inoculation in yeast extract medium supplemented with thiamine and nicotinic acid.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.370-377
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• 1998

본 연구는 황색포도상구균의 병원성 인자인 alpha-toxin, casular polysaccharides (CPS)와 fibronectin-binding protein (FnBP)을 이용해 실험동물인 토끼에서의 항체가 형성 능과 공격접종 후 방어능에 관한 연구를 위하여 수행되었으며 향후 젖소 유방염 아단위 항원 을 이용한 백신개발 가능성을 탐색하고자 수행되어졌다. 황색포도상구균의 alpha-toxin, capsu18r polysaccharides (CPS)91 fibronectin-binding protein (FnBP) 항원을 이통재 효소면 역측정법을 통한 혈중 IgG 항체가수준을 측정하였으며 alpha-toxin, capsular polysaccharides (CPS)와 fibronectin-binding protein (FnBP)으로 면역시킨 토끼에서 대조군의 토끼보다 혈 중 항체가 수준이 1차 면역 이후 유의성 있게 높았다 (p<0.05). 백신에 사용된 alpha-toxin, capsular polysaccharides (CPS)와 fibronectin-binding protein (FnBP) 항원중 capsular polysaccharides (CPS)가 다른 alpha toxin과 fibronectin-binding protein (FnBP)의 혈중항 체가 수준과 비교하여 볼 때 비교적 낮은 수준이었다. 세균을 혈중으로 공격접종한 후 대조군 과 백신접종군의 혈중내 세균제거율에 있어 대조군에 비해 백신접종군에서 유의성 있게 낮은 균수를 보였다 (p<0.05). 또한 장기내 균수측정실험결과 대조군의 장기보다 백신접종군에서 유의성 있게 세균수가 낮게 출현하였다 (p<0.05). 결론적으로 본 연구결과 황색포도상구균의 3가지 항훤 alpha-toxin, capsular polysaccharide와 재조합 fibronectin binding protein을 이 퐁한 실험동물에서 안단위 유방염 백신은 방어능이 있다고 생각된다.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.190-193
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• 2010

A 6-year-old, female, Siberian husky was referred with mucous diarrhea. On fecal examination, numerous clustered and individual large epithelial cells and rod-shaped, spore-forming bacteria were examined. By bacterial culture and molecular typing, the bacteria was identified as Clostridium perfringens (C. perfringens), and by toxin analysis of C. perfringens, production of $\alpha$-toxin was confirmed. Based on these results, the dog was diagnosed as enteritis caused by C. perfringens producing $\alpha$-toxin, and was treated with amoxicillin/clavulanate. After 1 week, the diarrhea was disappeared and no spore-forming bacteria were examined on fecal examination. This report shows that the rapid and exact diagnosis keeps a effective treatment for enteritis caused by C. perfringens producing $\alpha$-toxin in dogs.

• BMB Reports
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• v.38 no.4
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• pp.386-390
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• 2005

Based on the reported cDNA sequences of $BmK{\alpha}Txs$, the genes encoding toxin $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$ were amplified by PCR from the Chinese scorpion Buthus martensii Karsch genomic DNA employing synthetic oligonucleotides. Sequences analysis of nucleotide showed that an intron about 500 bp length interrupts signal peptide coding regions of $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$. Using cDNA sequence of $BmK{\alpha}Tx11$ as probe, southern hybridization of BmK genome total DNA was performed. The result indicates that $BmK{\alpha}Tx11$ is multicopy genes or belongs to multiple gene family with high homology genes. The similarity of $BmK{\alpha}$-toxin gene sequences and southern hybridization revealed the evolution trace of $BmK{\alpha}$-toxins: $BmK{\alpha}$-toxin genes evolve from a common progenitor, and the genes diversity is associated with a process of locus duplication and gene divergence.

• 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.

• BMB Reports
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• v.37 no.3
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• pp.292-297
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• 2004

The current model for the mechanism of action of the Bacillus thuringiensis Cry $\delta$-endotoxins involves the penetration of the ${\alpha}4-{\alpha}5$ hairpin into the target midgut epithelial cell membranes, followed by pore formation. In this study, PCR-based mutagenesis was employed to identify a critical residue within the ${\alpha}4-{\alpha}5$ loop of the 130-kDa Cry4A mosquito-larvicidal protein. Alanine-substitutions of two charged (Asp-198 and Asp-200) and four polar (Asn-190, Asn-195, Tyr-201 and Tyr-202) residues in the ${\alpha}4-{\alpha}5$ loop were performed. Like the wild-type, all of the mutant toxins were over-expressed as inclusion bodies in Escherichia coli. When E. coli cells expressing each mutant toxin were bioassayed against Aedes aegypti larvae, larvicidal activity was completely abolished for the substitution of only Tyr-202, while replacements at the other positions still retained a high level of toxicity. Further replacement of Tyr-202 with an aromatic side chain, phenylalanine, did not affect the toxicity. These results revealed a crucial role in toxin activity for the conserved aromatic residue at the 202 position within the ${\alpha}4-{\alpha}5$ loop of the Cry4A toxin.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.152-158
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• 2000

capsular polysaccharide(CPS), alpha toxin과 재조합 fibronectin binding protein (FnBP)으로 구성된 유방염 백신을 개발하여 야외효능실험을 수행하였다. 이 subunit 백신은 비유우 23두와 처녀우 20두를 대상으로 10개월동안 각각 수행되었다. 비유우는 매 3주간격으로 2회 백신접종을 하였으며 대조군은 PBS를 상유방림조절 주위에 피하주사하였다. 처녀우를 대상으로 한 실험에서는 분만 8주전부터 시작하여 매 3주간격으로 2회 비유우 백신접종부위와 동일하게 접종하였다. 접종후 비유우에서는 황색포도상구균에 의한 총유선내 감염율이 대조균에 비해 유의성있게 감소하였으며 (p<0.001) 처녀우에서도 총유선내 감염이 백신 접종균(1.6%)이 대조군(11.7%)에 비해 다음 비유기동안 유의성있게 낮았다. (p<0.001). 비유기동안 백신접종한 젖소의 체세포수는 변화가 없었으며 처녀우에서는 추가접종후 백신접종군에서 대조군의 체세포수에 비해 낮았지만 통계학적으로 유의성은 없었다(p>0.05). 본 실험결과 황색포도구균에 대한 유방염 아단위 백신은 비유우와 처녀우에서 체세포수를 증가시키지 않고 총 유선내 감염율을 낮추어주었다. 하지만 본 실험은 1군데의 목장을 대상으로 하였기 때문에 향후 대규모 목장을 대상으로 하는 유방염 백신의 야외효능실험이 심도있게 이루어져야 한다고 생각된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.71-75
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• 2015

Nicotinic acetylcholine receptors (nAChRs) are essential for neurotransmission and important therapeutic targets of diseases related to neurotransmission. A recent experimental study identified three residues (Lys185, Asp187, and Ile188) of the ${\alpha}6$ nAChR subunit as determinants of ${\alpha}$-conotoxin BuIA selectivity, yet how these residues confer toxin selectivity remains unclear. In this study, we performed all-atom molecular dynamics simulations with two toxin-bound ${\alpha}4{\beta}2$ nAChR systems: the wild-type ${\alpha}4{\beta}2$ and one in which we replaced the three ${\alpha}4$ subunit residues with three ${\alpha}6$ subunit residues identified in an experimental study (Tyr185Lys, Thr187Asp, and Arg188Ile). After mutation, Asp199 lost the salt bridge formed with Arg188 in the wild type located around loop C. Then, the loop C conformation changed and became more flexible than that of the wild type. We also detected reduced space between the toxin and the binding site in the mutant simulation, resulting in increased binding affinity to the toxin. Therefore, we propose a new Asp199 mutation that breaks the salt bridge and may produce similar selectivity to that of the Arg188 mutation.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.800-805
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• 2012

Licochalcone E was firstly isolated from licorice root in 2005, which belongs to the retrochalcone family. Studies on the biological activities of licochalcone E were in the initial stage. In the study, we demonstrated that licochalcone E has potent antimicrobial property against Staphylococcus aureus. Furthermore, via hemolysis, Western blot, and real-time RT-PCR assays, we have shown that subinhibitory concentrations of licochalcone E dose-dependently reduces the production of ${\alpha}$-toxin in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The data suggest that licochalcone E may deserve further investigation as a potential therapeutic against S. aureus infections, or the structure of licochalcone E may be used as a basis for chemical synthesis of novel anti-S. aureus compounds.

• Toxicological Research
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• v.4 no.1
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• pp.37-45
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• 1988

Primary cultures of adult rat hepatocytes were used to study in vitro cytotoxic effects of T-2 toxin on liver cells. When T-2 toxin was added to the culture, a significant depression of the hormonal induction of ${\alpha}$-aminoisobutyric acid (AIB) uptake and tyrosine aminotransferase (TAT) activity was observed. However, T-2 toxin did not affect the uptake of ouabain into hepatocytes. Protein synthesis was inhibited by T-2 toxin, but RNA synthesis was not severely affected. The inhibitory effects of T-2 toxin on protein synthesis was diminished rapidly with culture time and the hepatocytes culture maintained control level of protein synthesis within 24 hrs.