• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.710-718
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• 2011

Edema factor(EF) is a portion of anthrax toxin which produces edema when combined with protective antigen. This paper describes about technique for cloning, expression, purification and activity test of EF. Using the E. coli expression system, we could make recombinant EF protein although it's origin is Bacillus anthracis. And also we could culture massively and purify highly pure protein. Finally we confirm a enzyme activity of purified EF to increase intracellular cAMP level. Through establishing this technique, it can be possible to research about EF in depth and apply to expression and purification of many other protein in biology.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.275-280
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• 2005

Anthrax is an infectious disease caused by the gram-positive bacterium, Bacillus anthracis. Anthrax toxin is a tripartite toxin comprising of protective antigen (PA), lethal factor (LF) and edema factor (EF). PA is the receptor-binding component, which facilitates the entry of LF or EF onto the cytosol. LF is a zinc-dependent metalloprotease, which is a critical virulence factor in cytotoxicity of infected animals. Therefore, it is of interest to develop its potent inhibitors for the neutralization of anthrax toxin. The first step to identify the inhibitors is the development of a rapid, sensitive, and simple assay method with a high-throughput ability. Much efforts have been concentrated on the preparation of powerful assays and on the screening of inhibitors using these system. In the present study, we have tried to construct anthrax lethal factor in yeast expression system to prepare cell-based high-throughput assay system. Here, we have shown the results covering the construction of a new vector system, subcloning of LF gene, and the expression of target gene. Our results are first trial to express LF gene in eukaryote and provide the basic steps in design of cell-based assay system.

• Journal of Photoscience
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• v.9 no.2
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• pp.323-325
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• 2002

Bacillus Anthracis is the causative agent of anthrax. The major virulence factors are a poly-D glutamic acid capsule and three-protein component exotoxin, which is collectively known as anthrax toxin, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa). These three proteins individually have no known toxic activities, but in combination with PA form two toxins (lethal toxin and edema toxin), causing different pathogenic responses in animals and cultured cells. However, it remains to be elucidated for pathogenic mechanism of anthrax toxin. In this study, we constructed toxin component in bacterial overexpression system and purified the native toxin from Bacillus anthracis delta sterne F32 using FPLC system. Recombinant toxin showed high homogeneity and rapid purification processes. Also, this recombinant toxin was comparable to B. anthracis native toxin in terms of cytotoxic effects on cultured cell lines.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1784-1790
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• 2006

Bacillus anthracis is a causative agent of anthrax. Anthrax toxins are composed of a protective antigen (PA), lethal factor (LF), and edema factor (EF), in which the PA is a central mediator for the delivery of the two enzymatic moieties LF and EF. Therefore, the PA has been an attractive target in the prevention and vaccinization for anthrax toxin. Recently, it has been reported that the molecule consisting of multiple copies of PA-binding peptide, covalently linked to a flexible polymer backbone, blocked intoxification of anthrax toxin in an animal model. In the present study, we have screened novel diverse peptides that bind to PA with a high affinity (picomolar range) from an M13 peptide display library and characterized the binding regions of the peptides. Our works provide a basis to develop novel potent inhibitors or diagnostic probes with a diverse polyvalence.

• Journal of Life Science
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• v.28 no.11
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• pp.1361-1368
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• 2018

Inflammation is the most common condition in the human body. Tissue damage triggers inflammation, together with vasodilation and increased blood flow at the inflamed site, resulting in edema. Inflammatory responses are also triggered by lipopolysaccharide (LPS), a Toll-like receptor Enterococcus faecalis, a gram-positive organism, has been reported to possess immunomodulatory and preventive activities; however, its use may present risks of sepsis and other systemic infections. Heat-killed Enterococcus faecalis (EF-2001) has been reported to induce antitumor activity, but its effects on inflammation are not known. In the present study, we investigated the effect of EF-2001 on LPS-induced macrophage inflammatory responses. EF-2001 treatment reduced nitric oxide (NO) production, indicating suppression of inflammatory reactions. EF-2001 showed no cytotoxicity in macrophages. Further investigation of the anti-inflammatory mechanism of EF-2001 indicated that EF-2001 reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2. EF-2001 also reduced f the LPS induction of several inflammatory molecules involved in the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and mitogen-activated protein kinase pathways, including ERK, JNK, and p38 phosphorylation, in a concentration-dependent manner. Additionally, EF-2001 inhibited Akt phosphorylation and increased the expression of the inhibitory ${\kappa}B$ ($I{\kappa}B$) protein, an inhibitor of $NF-{\kappa}B$. EF-2001 also inhibited the nuclear translocation of p65. These results suggest that EF-2001 has anti-inflammatory properties and may be useful for treating inflammatory diseases.

• BMB Reports
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• v.44 no.12
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• pp.811-815
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• 2011

Inhalational anthrax is caused by B. anthracis, a virulent sporeforming bacterium which secretes anthrax toxins consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). LF is a Zn-dependent metalloprotease and is the main determinant in the pathogenesis of anthrax. Here we report the identification of a lead small-molecule inhibitor of anthrax lethal factor by screening an available synthetic small-molecule inhibitor library using fluorescence-based high-throughput screening (HTS) approach. Seven small molecules were found to have inhibitory effect against LF activity, among which SM157 had the highest inhibitory activity. All theses small molecule inhibitors inhibited LF in a noncompetitive inhibition mode. SM157 and SM167 are from the same family, both having an identical group complex, which is predicted to insert into S1' pocket of LF. More potent small-molecule inhibitors could be developed by modifying SM157 based on this identical group complex.