• Journal of Microbiology
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• v.35 no.4
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• pp.323-326
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• 1997

Toxin protein from Ustilago maydis virus SH14 isolated in Korea was purified using ethanol precipitation, cation exchange, gel filtration and anion exchange chromatography. The molecular weight of the purified protein was estimated to be 8.3 kDa by SDS-PAGE analysis. The Nterminal sequence of the protein is L-G-I-N-C(K)-R-G-S-S-Q--C(K)-G-L-S-G which is highly homologous with that of P4 toxin, but the amino acid composition and electrophoretic mobility in a native PAGE of the toxin protein were totally different from those of P4 toxin respectively. The SH14 toxin was shown to have immunological cross-reactivity about 50% with P4 toxin when examined by Western hybridization.

• 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.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.115-122
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• 1995

Effects of staurosporine, genistein and pertussis toxin on superoxide and HOCl production in C5a- or PMA-activated neutrophils were investigated. A C5a-induced superoxide and $H_2O_2$ production was inhibited by staurosporine, genistein and pertussis toxin. The stimulatory effect of PMA was inhibited by staurosporine but was not affected by pertussis toxin, whereas it was further promoted by genistein. Staurosporine and genistein inhibited superoxide production by sodium fluoride, but pertussis toxin did not affect it. PMA-induced $H_2O_2$ production was inhibited by staurosporine but was not affected by pertussis toxin. Genistein did not show a stimulatory effect on PMA-induced $H_2O_2$ production. Staurosporine and pertussis toxin inhibited HOCl production by C5a- or PMA, whereas genistein stimulated it. C5a-or PMA-induced myeloperoxidase release was inhibited by genistein, in this response the effect of pertussis toxin was not detected. Staurosporine did not affect the stimulatory effect of PMA on the release. Myeloperoxidase activity was markedly increased by genistein but was not affected by staurosporine and pertussis toxin. These results indicate that the respiratory burst of neutrophils may be regulated by protein kinase C and protein tyrosine kinase. Superoxide production induced by the direct activation of protein kinase C might be affected by protein tyrosine kinase oppositely. Genistein probably pro-motes HOCl production by activating myeloperoxidase.

• 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.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.318-323
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• 1995

The effect of AF-toxin I produced by the strawberry pathotype of Alternaria alternata on the protein synthesis of susceptible strawberry protoplasts was examined by using the radiolabeled amino acids. The incorporation of the radiolabeled amino acids into newly synthesized proteins in the strawberry protoplasts was stimulated by the toxin treatment at relatively low concentrations (2.2$\times$10-11 to 2.2$\times$10-9 M), but not at higher concentrations (2.2$\times$10-8 to 2.2$\times$10-6 M). An one-dimensional SDS-polyacrylamide gel electrophoresis revealed no detectable differences in the proteins synthesized in both the toxintreated and untreated protoplasts. The susceptible strawberry protoplasts were treated with AF-toxin I and stained with Fluostain I to detect the extracellular polysaccharides. The toxin treatment induced the accumulation of extracellular polysccharides in a dose-dependent manner. These results indicate a transient activation of cellular metabolism in the susceptible cells by the toxin exposure.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.451-455
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• 1996

Physiological studies on the expression of Bacillus thuringiensis subsp. tenebrionis (Btt) gene coding for insecticidal protein in recombinant Escherichia coli 537 were carried out to identify optimal culture condition. It was necessary to shift culture temperature from 30 to $42^{\circ}C$ to express the gene. Expression of the Btt toxin gene by recombinant E. coli 537 began within one hour after induction. Complex nitrogen sources increased production of the insecticidal protein. The total insecticidal protein was 0.5 g/I when using yeast extract as a complex nitrogen source. Soybean hydrolysate showed apparently the highest induction efficiency. After induction, the cellular content of the insecticidal protein was 5.4 times higher than it had been before induction. The optimal cultivation strategy was found to grow cells for 7hours at $30^{\circ}C$ and then 5-8 hours at $42^{\circ}C$. The optimal cultivation pH for the production of insecticidal protein was 6.5. The Btt toxin produced by the recombinant E. coli 537 was found to have the same level of potency against Colorado potato beetle as the original toxin.

• Genomics & Informatics
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• v.21 no.1
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• pp.7.1-7.11
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• 2023

The gram-positive bacterium Listeria monocytogenes is an important foodborne intracellular pathogen that is widespread in the environment. The functions of hypothetical proteins (HP) from various pathogenic bacteria have been successfully annotated using a variety of bioinformatics strategies. In this study, a HP Imo0888 (NP_464414.1) from the Listeria monocytogenes EGD-e strain was annotated using several bioinformatics tools. Various techniques, including CELLO, PSORTb, and SOSUIGramN, identified the candidate protein as cytoplasmic. Domain and motif analysis revealed that the target protein is a PemK/MazF-like toxin protein of the type II toxin-antitoxin system (TAS) which was consistent with BLASTp analysis. Through secondary structure analysis, we found the random coil to be the most frequent. The Alpha Fold 2 Protein Structure Prediction Database was used to determine the three-dimensional (3D) structure of the HP using the template structure of a type II TAS PemK/MazF family toxin protein (DB ID_AFDB: A0A4B9HQB9) with 99.1% sequence identity. Various quality evaluation tools, such as PROCHECK, ERRAT, Verify 3D, and QMEAN were used to validate the 3D structure. Following the YASARA energy minimization method, the target protein's 3D structure became more stable. The active site of the developed 3D structure was determined by the CASTp server. Most pathogens that harbor TAS create a crucial risk to human health. Our aim to annotate the HP Imo088 found in Listeria could offer a chance to understand bacterial pathogenicity and identify a number of potential targets for drug development.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.177-180
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• 1992

Among 120 U. maydis strains isolated in Korea 14 different strains containing specific viral dsRNA segments were analyzed for the distribution of dsRNA and the production of toxin protein. Several distinctive dsRNA patterns were identified, 9 cases of P type with typical H, M and L ds RNA and one case of non-P-type, the frequency of a specific isolate was decreased with increasing number of dsRNA segments. The presence of dsRNA had no effect on the cultural or morphological phenotype of the host. Two isolates containing P type dsRNA segments appeared to produce toxin protein (killer strains) which inhibited the growth of 4 isolates (sensitive strain) with different susceptibility. Two killer strains contain unique M dsRNA segment which may code for toxin protein. However, the presence of toxin-sensitive strains among dsRNA-free isolates was similar to that of ds RNA containing strains.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.390-396
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• 1995

Bacillus sphaericus 1593 is a larvicidal toxin-producing mosquitocidal bacterium. The toxin contains a parasporal crystalline inclusion which is composed of a protein that is activated under alkaline condition. To enhance alkaline environment around toxin protein, cryptic plasmid cured, B. sphaericus 1593 was transformed by the Bacillus pasteurii urease gene which generate ammonia from urea. Transformant produced urease at about 80% more than wild type strain. B. sphaericus 1593, and the urease gene was stably maintained. It also produced crystalline toxin protein at the same level as the wild type strain B. sphaericus 1593.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.772-776
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• 2004

Physiological and molecular characteristics of Bacillus thuringiensis SR6 and SR8 were investigated, and phase contrast and electron microscopies revealed that a large rhomboidal crystal protein was present in the sporulating cells. SDS-PAGE and Western blot analyses showed that B. thuringiensis SR8 produced 70 kDa protein much more than other proteins, and that the 70 kDa protein could bind to the antibody of B. thuringiensis subsp. tenebrionis-crystal toxin protein, indicating that the crystal 70 kDa protein has an immunological homology with B. thuringiensis subsp. tenebrionis-crystal toxin protein. The DNA fragment of B. thuringiensis subsp. tenebrionis-toxin gene was detected in B. thuringiensis SR6 and SR8 by using PCR amplification analysis. Furthermore, the insect bioassay showed the insecticidal activity against Colorado potato beetle larvae. Based on the physiological and molecular similarities to B. thuringiensis subsp. tenebrionis, it is suggested that the B. thuringiensis SR6 and SR8 may be mutants of the B. thuringiensis subsp. tenebrionis strain overexpressing the crystal of 70 kDa toxin protein.