• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.753-758
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• 2000

Human leptin is identified as a 16kDa (146 amino acids) protein secreted from adipocytes which influences body weight homeostasis. In order to produce active leptin, the human obese gene coding for leptin was expressed in Bacillus subtilis WB600 strain which is deficient in six extracellular proteases. The recombinant leptin was produced in a culture supernatant, and in a culture supernatant, it was contained as high as 48% for total proteins. After simple purification steps, which consisted of ammonium sulfate precipitation and anion-exchange column chromatography, 2.3 mg of leptin with a purity greater than 95% was obtained from the 0.51 culture with the recovery yield of 38.3%. The purified leptin showed the correct folding structure with one disulfied bond.

• 한국양식학회지
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• 제19권1호
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• pp.40-46
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• 2006

Bacillus subtilis strain with highly active chitosanase was isolated from the intestine of Sebastiscus marmoratus (scorpion fish). It was named as Bacillus subtilis CH1 by morphological, biochemical and 165 rRNA gene analysis. The optimal conditions for chitosanase production were investigated. The optimum carbon and nitrogen sources for Bacillus stibtilis CH1 were 2% starch and 1% yeast extract respectively. Unlike other chitosanases, the expression of this chitosanase was not induced or slightly induced with chitosan. The chitosanase secreted into the medium were concentrated with ammonium sulfate precipitation and purified by gel permeation chromatography. The molecular weight of purified chitosanase was 30 kDa. The optimum pH and temperature of purified chitosanase were 5.5 and $60^{\circ}C$ respectively. The purified chitosanase was continuously thermostable at $40^{\circ}C$ and showed stable activity between pH 6.0 and 8.0. Chitosanase activity of Bacillus subtilis CH1 under optimum condition was 4.1 units/ml.

• Journal of Microbiology and Biotechnology
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• 제10권4호
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• pp.547-550
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• 2000

The yeast Williopsis californica was shown to secrete a unique broad-spectrum killer toxin (Wicaltin) with antifungal activity against 14 yeast genera, including yeast-like and mycelial forms of the human pathogens Candida albicans and Sporothrix schenkii. Agar diffusion bioassays indicated that its activity was more pronounced than the antifungal potential of frequently used antimycotics; 0.07 pmol Wicaltin showed the same toxicity as 0.2 pmol miconazole and 29 pmol clotrimazole. Since the toxin's primary target would appear to be the yeast cell wall, Wicaltin may be attractive in combatting clinically relevant yeast and fungal infections.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.641-646
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• 1996

[$\gamma$-$^{32}$P]ATP was used to test phosphorylation of membrane proteins of mating type a cells of heterobasidiomycetous yeast Rhodosporidium toruloides separated by non-denaturing electrophoresis. The phosphoprotein was observed in the membrane proteins. The phosphorylation was inhibited by the pheromone rhodotorucine A (Rh. A) secreted by mating type A of the yeast. Rh. A didn't inhibit the phosphorylation in the presence of a trigger peptidase (TPase) inhibitor, antipain. Partially digested Rh. A by trypsin maintained the phosphorylation inhibitory activity. These results show that TPase activity plays an important role in the transduction of pheromone signal in the yeast.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.266-273
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• 1991

Hirudin, a 65-amino acid protein isolated from the salivary gland of the bloodsucking leech, Hirudo medicinalis, is a potent thrombin-specific inhibitor and blocks the thrombin-mediated conversion of fibrinogen to fibrin in clot formation. We have studied the gene expression and secretion of hirudin in yeast. Saccharomyces cerevisiae. A gene coding for hirudin was synthesized based on the amino acid sequence and cloned into a yeast expression vector $YEG{\alpha}-1$ containing the ${\alpha}-mating$ factor pre-pro leader sequence and galactose-inducible promoter, GALl0. Recombinant S. cerevisiae was found to secrete biologically active hirudin into the extracellular medium. The secreted recombinant hirudin was recovered from the culture medium and purified with ultrafiltration and reverse phase high performance liquid chromatography. Approximately 1 mg of hirudin per liter was produced under suboptimal culture conditions and brought to about 90% purity in two steps of purification.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.23-23
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• 2015

Rice blast disease caused by M. oryzae is the most devastating fungal disease in rice. During the infection process, M. oryzae secretes a large number of glycosyl hydrolase (GH) proteins into the apoplast to digest host cell wall and assist fungal ingress into host tissues. In this study, we identified a novel M. oryze arabinofuranosidase B (MoAbfB) which is secreted during fungal infection. Live-cell imaging exhibited that fluorescent labeled MoAbfB was highly accumulated in fungal invasive structures such as appressorium, tips of penetration peg, biotrophic interfacial complex (BIC), as well as invasive hyphal tip. Deletion of MoAbfB mutants extended biotrophic phase followed by enhanced disease severity, whereas, over-expression of OsMoAbfB mutant induced rapid defense responses and enhanced rice resistance to M. oryzae infection. Furthermore, exogenous treatment of MoAbfB protein showed inhibition of fungal infection via priming of defense gene expression. We later found that the extract of MoAbfB degraded rice cell wall fragments could also induce host defense activation, suggesting that not MoAbfB itself but oligosaccharides (OGs) derived from MoAbfB dissolved rice cell wall elicited rice innate immunity.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.629-633
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• 2009

The present study investigated the antimetastatic property of chitosan oligosaccharides (COS) by evaluating motility, invasion, and the amount and activity of MMP-9 in MDA-MB-231 human breast carcinoma cells. Treatment of MDA-MB-231 cells with increasing concentrations of COS led to a concentration-dependent decrease in cell migration. COS significantly inhibited the invasion of MDA-MB-231 cells through a Matrigel-coated membrane. The treatment of MDA-MB-231 cells with COS reduced the amounts of secreted MMP-9. The activity and amount of MMP-9 protein in MDA-MB-231 cells were decreased by treatment with COS and occurred in a concentration-dependent manner. Our data indicated that COS can serve as a potential novel therapeutic candidate for the treatment of metastatic breast cancer.

• 통합자연과학논문집
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• 제10권1호
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• pp.20-26
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• 2017

Chemerin receptor, which predominantly expressed in immune cells as well as adipose tissue, was found to stimulate chemotaxis of dendritic cells and macrophages to the site of inflammation. Chemerin is a widely distributed multifunctional secreted protein implicated in immune cell migration, adipogenesis, osteoblastogenesis, angiogenesis, myogenesis, and glucose homeostasis. Recent studies suggest chemerin may play an important role in the pathogenesis of obesity and insulin resistance and it becomes a potential therapeutic target for treating type II diabetes. The crystal structure of chemerin receptor has not yet been resolved. Therefore, in the present study, homology modelling of CMKLR1 was done utilizing the crystal structure of human angiotension receptor in complex with inverse agonist olmesartan as the template. Since the template has low sequence identity, we have incorporated both threading and comparative modelling approach to generate the three dimensional structure. 3D models were generated and validated. The reported models can be used to characterize the critical amino acid residues in the binding site of CMKLR1.

• Mycobiology
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• 제47권1호
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• pp.112-119
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• 2019

Compounds from Lingzhi has been demonstrated the ability for inhibiting tyrosinase (a key enzyme in melanogenesis) activity. In this study, we investigated the anti-melanogenic activity from the submerged mycelial culture of Ganoderma weberianum and elucidated the skin lightening mechanism by B16-F10 murine melanoma cells. From the cellular context, several fractionated mycelium samples exhibited anti-melanogenic activity by reducing more than 40% extracellular melanin content of B16-F10 melanoma cells. In particular, the fractionated chloroform extract (CF-F3) inhibited both secreted and intracellular melanin with the lowest dosage (25 ppm). Further analysis demonstrated that CF-F3 inhibited cellular tyrosinase activity without altering its protein expression. Taken together, our study has demonstrated that the chemical extracts from submerged mycelial culture of G. weberianum have the potential to serve as an alternative anti-melanogenic agent.

• International Journal of Oral Biology
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• 제49권2호
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• pp.34-41
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• 2024

Extracellular traps (ETs), primarily composed of DNA and antibacterial peptides, are mainly secreted by neutrophils to inhibit pathogen spread and eliminate microorganisms. Recent reports suggest that microglia can also secrete ETs, and these microglial ETs are associated with various neurological conditions, including nerve injury, tumor microenvironment, and ischemic stroke. However, the components and functions of microglial ETs remain underexplored. Secretagogin (Scgn), a calcium-sensor protein, plays a crucial role in the release of peptide hormones, such as insulin, in endocrine cells; however, its function in immune cells, including microglia, is not well understood. Our study demonstrated that Scgn deficiency can lead to the formation of abnormal ETs. We hypothesized that this may involve the c-Jun N-terminal kinase-myeloperoxidase pathway and autophagy.