• 대한수의학회지
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• 제39권2호
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• pp.301-310
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• 1999

Anthrax caused by Bacillus anthracis is one of the most important zoonotic diseases. The bacterium produces several virulence factors. Of the factors, protective antigen (PA) of tripatite toxin has been identified as a central component in the pathogenesis of anthrax. However, precise roles of PA and other cellular components in the reaction with the target cells remain to be elucidated, especially in the initial stage of the disease. Three B anthracis antigens were prepared for investigation; PA, sonicated cellular antigens (S-Ag) and formalin-inactivaed whole cell antigens (W-Ag). PA was purified from culture supernatant of the bacterium using FPLC system with MonoQ. S-Ag and W-Ag were prepared by sonication and formalin inactivation of the cultured cells, respectively. Purity of the antigens was confirmed by SDS-PAGE and Western blot analysis. The roles of these antigens in the production of inflammatory mediators such as NO, IL-6 and $TNF{\alpha}$ from mouse peritoneal macrophages were investigated. PA alone did not induce the production of the inflammatory mediators while the other antigens, S-Ag and W-Ag, did in a dose and time dependent manner. These results suggested that in addition to major virulence factors, other cellular antigens are also involved in the initial stage of the disease by the induction of inflammatory mediators.

• 한국응용곤충학회지
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• 제33권3호
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• pp.178-183
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• 1994

Bacillus thuringiensis kurstaki와 aizawai의 내독소단백질을 알카리용액 또는 트립신, 곤충소화액 드응ㄹ 처리하여 전기영동한 후 단백질팬턴을 비교하였다. 두 균주의 주요 결정단백질은 130kd와 64kd의 단백질이었으며, 소화액이나 효소로 처리한 경우 공통적으로 62kd의 활성독소가 생성되었다. 그러나, aizawai는 kurstaki에 비해 현저히 적은 양의 62kd 단백질을 생성하였다. 흰불나방의 유충이 Bacillus thuringiensis 독소를 섭식하였을 때 지방체를 비롯한 몇 가지 조직에서 45kd의 스트레스 단백질이 유발되었는데 이 단백질은 열충격이나 저온 충격시에도 마찬가지로 생성되었다.

• Natural Product Sciences
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• 제26권4호
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• pp.259-267
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• 2020

Snakebite is a severe medical, economic, and social problem across the world, mostly in the tropical and subtropical area. These regions of the globe have typical of the world's venomous snakes present where access to prompt treatment is limited or not available. Snake venom is a complex mixture of toxin proteins like neurotoxin and cardiotoxin, and other enzymes like phospholipase A2 (PLA2), haemorrhaging, transaminase, hyaluronidase, phosphodiesterase, acetylcholinesterase, cytolytic and necrotic toxins. Snake venom shows a wide range of biological effects like anticoagulation or platelet aggregation, hemolysis, hypotension and edema. Phospholipase A2 is the principal constituent of snake venom; it catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid, which is the precursor of eicosanoids including prostaglandins and leukotrienes. The information regarding the structure and function of the phospholipase A2 enzyme may help in treating the snakebite victims. This review article constitutes a brief description of the structure, types, mechanism occurrence, and tests of phospholipase A2 and role of components of medicinal plants used to inhibit phospholipase A2.

• 한국식품영양과학회지
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• 제35권2호
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• pp.212-218
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• 2006

독화된 진주담치 (blue mussel, Mylilus edulis)를 pH 처리, 온도별 저장 그리고 가열에 의한 마비성 패류독의 독성과 독조성 특성 변화는 다음과 같다. pH 3으로 조절한 시료가 14.1 MU/g$(100\%)$으로 가장 높은 독성이 검출되었고, pH 5는 12.9 MU/g$(92.1\%)$, pH 7은 9.0 MU/g$(63.8\%)$으로 검출되었으나, 마비성 패류독은 독성이 불안정한 알칼리 조건인 pH 9에서는 3.6 Mu/g$(25.5\%)$, pH 10은 0.8 Mu/g$(5.7\%)$으로 독성 이 검출되었다. 저장기간 동안의 독성은 pH(3, 5, 7, 9) 그리고 온도(30, -5, $20^{\circ}C$)에서 5일$(19.9\~65.3\%)$까지 현저하게 감소하였으나, 5일 후부터 30일까지는 약간의 독성이 감소하였다. 그리고 더 높은 온도에서 저장에서는 독성이 더 빨리 감소하였다. 대부분의 성분인 C군(C1, C2)과 GTX1,2,3,4, STX 그리고 dcSTX으로 8개의 성분이 검출되었고, 8개의 독성분 중에서 GTX1,4, STX 그리고 dcSTX는 모든 가공 조건에서 독성이 감소함에 따라 제일 먼저 감소하였다. 독성이 기준 독성치(4 MU/g)보다 3배 이상이더라도 마쇄된 패류 육에 pH를 알칼리 (pH 7이상)로 처리하고, 10분의 가열에 의해 독성을 완전히 제거할 수 있었다.

• BMB Reports
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• 제52권8호
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• pp.496-501
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• 2019

Conventionally, immunotoxins have been produced as a single polypeptide from fused genes of an antibody fragment and a toxin. In this study, we adopted a unique approach of chemical conjugation of a toxin protein and an antibody fragment. The two genes were separately expressed in Escherichia coli and purified to high levels of purity. The two purified proteins were conjugated using a chemical linker. The advantage of this approach is its ability to overcome the problem of low recombinant immunotoxin production observed in some immunotoxins. Another advantage is that various combinations of immunotoxins can be prepared with fewer efforts, because the chemical conjugation of components is relatively simpler than the processes involved in cloning, expression, and purification of multiple immunotoxins. As a proof of concept, the scFv of trastuzumab and the PE24 fragment of Pseudomonas exotoxin A were separately produced using E. coli and then chemically crosslinked. The new immunotoxin was tested on four breast cancer cell lines variably expressing HER2. The chemically crosslinked immunotoxin exhibited cytotoxicity in proportion to the expression level of HER2. In conclusion, the present study revealed an alternative method of generating an immunotoxin that could effectively reduce the viability of HER2-expressing breast cancer cells. These results suggest the effectiveness of this method of immunotoxin crosslinking as a suitable alternative for producing immunotoxins.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1051-1058
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• 2014

Platelet-activating factor receptor (PAFR) plays an important role in bacterial infection and inflammation. We examined the effect of the bacterial cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) on PAFR expression in THP-1, a monocyte-like cell line. LPS and aLTA, but not pLTA, significantly increased PAFR expression, whereas priming with pLTA inhibited LPS-mediated or aLTA-mediated PAFR expression. Expression of Toll-like receptor (TLR) 2 and 4, and CD14 increased with LPS and aLTA treatments, but was inhibited by pLTA pretreatment. Neutralizing antibodies against TLR2, TLR4, and CD14 showed that these receptors were important in LPS-mediated or aLTA-mediated PAFR expression. PAFR expression is mainly regulated by the nuclear factor kappa B signaling pathway. Blocking PAF binding to PAFR using a PAFR inhibitor indicated that LPS-mediated or aLTA-mediated PAF expression affected TNF-${\alpha}$ production. In the mouse small intestine, pLTA inhibited PAFR, TLR2, and TLR4 expression that was induced by heat-labile toxin. Our data suggested that pLTA has an anti-inflammatory effect by inhibiting the expression of PAFR that was induced by pathogenic ligands.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1149-1155
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• 2020

Silage is one of the main feed components of ruminants around the world and can make up about 50-80% of the rations of dairy cows during the winter. The aim of this study was to evaluate the usability of oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) aqueous and ethanol extracts to improve the hygienic quality of perennial ryegrass, red clover and blue alfalfa silage samples and estimate their effect on mycotoxins concentrations. Under laboratory conditions, 63 silage samples (21 perennial ryegrass, 21 blue alfalfa, 21 red clover) were fermented with inserted aqueous and ethanol extracts of oregano and thyme and two commercial inoculants with mesophilic lactic acid bacteria. After 96 days of fermentation, in silage samples were established fermentation parameters, microbiological status and mycotoxins concentrations. It was determined that the best results for achieving hygienic quality of perennial ryegrass and red clover silage samples was by insertion of aqueous and ethanol extracts of oregano and thyme. In blue alfalfa samples, the best results of silage hygienic indicators were determined by inserting aqueous and ethanol extracts of oregano. Aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEA) and T-2 toxin concentrations in perennial ryegrass, red clover and blue alfalfa silage samples were best reduced by inserting aqueous and ethanol extracts of oregano and thyme. The present study shows that these extracts can be used to improve silage hygienic quality, reduce mycotoxins concentrations and thus ensure the wellness of cattle.

• The Korean Journal of Physiology and Pharmacology
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• 제16권5호
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• pp.343-348
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• 2012

Blocking or regulating $K^+$ channels is important for investigating neuronal functions in mammalian brains, because voltage-dependent $K^+$ channels (Kv channels) play roles to regulate membrane excitabilities for synaptic and somatic processings in neurons. Although a number of toxins and chemicals are useful to change gating properties of Kv channels, specific effects of each toxin on a particular Kv subunit have not been sufficiently demonstrated in neurons yet. In this study, we tested electro-physiologically if heteropodatoxin2 ($HpTX_2$), known as one of Kv4-specific toxins, might be effective on various $K^+$ outward currents in CA1 neurons of organotypic hippocampal slices of rats. Using a nucleated-patch technique and a pre-pulse protocol in voltage-clamp mode, total $K^+$ outward currents recorded in the soma of CA1 neurons were separated into two components, transient and sustained currents. The extracellular application of $HpTX_2$ weakly but significantly reduced transient currents. However, when $HpTX_2$ was added to internal solution, the significant reduction of amplitudes were observed in sustained currents but not in transient currents. This indicates the non-specificity of $HpTX_2$ effects on Kv4 family. Compared with the effect of cytosolic 4-AP to block transient currents, it is possible that cytosolic $HpTX_2$ is pharmacologically specific to sustained currents in CA1 neurons. These results suggest that distinctive actions of $HpTX_2$ inside and outside of neurons are very efficient to selectively reduce specific $K^+$ outward currents.

• 한국수산과학회지
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• 제46권2호
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• pp.154-159
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• 2013

The AOAC Mouse Bioassay method (MBA) has been widely used for routine monitoring of paralytic shellfish poisoning (PSP) for more than 50 years. However, this method has low sensitivity and experiences interference from other components in the extract. Also, ethical issues have been raised against the continued use of this live-mouse assay. To establish an alternative method for PSP analysis, we attempted to develop PSP analysis conditions using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS analysis of reference material showed very reasonable accuracy, and the analysis time was just 15 min. However, the recovery rate of toxin spike samples using the LC-MS/MS analysis was 59.4-91.0%. We also attempted to remove the matrix effect using shellfish extracts, but recoveries of C1 and C2 did not improve. A comparison between the results of MBA and LC-MS/MS analysis revealed good correlations, with values of 0.8878 and 0.9211 for oyster and mussel matrices, respectively.

• Ocean and Polar Research
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• 제41권4호
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• pp.289-309
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• 2019

Marine microalgae have long been used as food additives and feeds for juvenile fish and invertebrates as their nutritional content is beneficial for humans and marine aquaculture species. Recently, they have also been recognized as a promising source for cosmeceutical, nutraceutical, and pharmaceutical products as well as biofuels. Marine microalgae of various species are rich in multiple anti-oxidant phytochemicals and their bioactive components have been employed in cosmetics and dietary supplements. Oil contents in certain groups of marine microalgae are extraordinarily rich and abundant and therefore have been commercialized as omega-3 and omega-6 fatty acid supplements and mass production of microalgae-based biodiesels has been demonstrated by diverse research groups. Numerous natural products from marine microalgae with significant biological activities are reported yearly and this is attributed to their unique adaptive abilities to the great diversity of marine habitats and harsh conditions of marine environments. Previously unknown toxin compounds from red tide-forming dinoflagellates have also been identified which opens up potential applications in the blue biotechnology sector. This review paper provides a brief overview of the biotechnological potentials of Korean marine microalgae. We hope that this review will provide guidance for future marine biotechnology R&D strategies and the various marine microalgae-based industries in Korea.