• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2365-2368
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• 2012

The $11{\beta}$-hydroxysteroid dehydrogenase type 1 ($11{\beta}$-HSD1) enzyme is involved in modulation of glucocorticoid activity within target tissues. This enzyme may contribute to obesity and/or metabolic disease through its action in adipose or liver tissue. Inhibition of $11{\beta}$-HSD1 has major therapeutic potential for glucocorticoid-associated diseases, including obesity, diabetes (wound healing), and muscle atrophy. To develop such therapeutics, we performed a pharmacophore-based virtual screening (VS) for identification of novel $11{\beta}$-HSD1 inhibitors and found that the VS hit compounds show potent inhibition of $11{\beta}$-HSD1 enzyme activity. Further, we present a binding model for active compounds. The proposed pharmacophore may serve as a useful guideline for future design of new chemical entities as $11{\beta}$-HSD1-targeted antidiabetic agents.

• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.670-680
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• 2018

Acanthophysium sp. KMF001, a wood rotting fungus, produces a strong crude enzyme complex that efficiently produces simple sugars from wood. The transcriptomic analysis of Acanthophysium sp. KMF001 identified 14 genes for putative glycoside hydrolases. Among them, isotig01043 was expressed heterogeneously in Escherichia coli BL21(DE3), and the expressed protein exhibited an endo-${\beta}$-1,4-xylanase activity which showed the optimum reaction at pH 5.0 and $30^{\circ}C$. The enzyme kinetic values of $K_m$ and $V_{max}$ were 25.92 mg/ml and $0.628{\mu}mole/mg/ml$, respectively. The enzymatic characteristics of the expressed xylanase showed a typical fungal xylanase. However, the bioinformatics analysis suggested that the protein encoded by isotig01043 was a novel xylanase based on a low identity when it was compared with the closest protein in the NCBI database and a similar protein domain with GH16_fungal_Lam16A_glucanase, which had not been earlier suggested as a xylanase.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2181-2186
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• 2012

Dendrimers are a novel class of nonlinear polymers and due to their extensive applications in different fields, called versatile polymers. Polyamidoamine (PAMAM) dendrimers are one of the most important dendrimers that have many applications in nanobiotechnology and industry. Generally aldehyde terminated dendrimers are prepared by activation of amine terminated dendrimers by glutaraldehyde which has two problems, toxicity and possibility of crosslink formation. In this study, novel aldehyde-terminated PAMAM dendrimer was prepared and used for covalent immobilization of trypsin by the aim of finding a special reagent which can prevent crosslinking and deactivation of the enzyme. For this purpose aminoacetaldehydedimethylacetal (AADA) was used as spacer group between aldehyde-terminated PAMAM and trypsin.The findings of this study showed that immobilization of trypsin not only resulted higher optimal temperature, but also increased the thermal stability of the immobilized enzyme in comparison to the free enzyme.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1081-1089
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• 2008

A novel ginsenoside-hydrolyzing ${\beta}$-glucosidase was purified from Paecilomyces Bainier sp. 229 by a combination of Q-Sepharose FF, phenyl-Sepharose CL-4B, and CHT ceramic hydroxyapatite column chromatography. The purified enzyme was a monomeric protein with a molecular mass estimated to be 115 kDa. The optimal enzyme activity was observed at pH 3.5 and $60^{\circ}C$. It was highly stable within pH 3-9 and at temperatures lower than $55^{\circ}C$. The enzyme was specific to ${\beta}$-glucoside. The order of enzyme activities against different types of ${\beta}$-glucosidic linkages was ${\beta}$-(1-6)>${\beta}$-(1-2)>${\beta}$-(1-4). The enzyme converted ginsenoside Rb1 to CK specifically and efficiently. An 84.3% amount of ginsenoside Rb1, with an initial concentration of 2 mM, was converted into CK in 24 h by the enzyme at $45^{\circ}C$ and pH 3.5. The hydrolysis pathway of ginsenoside Rb1 by the enzyme was $Rb1{\to}Rd{\to}F2{\to}CK$. Five tryptic peptide fragments of the enzyme were identified by a newly developed de novo sequencing method of post-source decay (PSD) matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. By comparing the five identified peptide sequences with the NCBI database, this purified ${\beta}$-glucosidase proves to be a new protein that has not been reported before.

• 생명과학회지
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• 제23권1호
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• pp.110-115
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• 2013

Extracellular 지질분해효소를 생산하는 균주 AR1은 일본 벳부 온천수에서 분리하였다. 분리된 균주의 16s rRNA 염기서열을 분석하고 계통학적으로 분류한 결과, AR1 균주는 신규 Geobacillus sp.에 속하는 것으로 동정되었다. 본 연구는 Geobacillus sp. AR1 균주의 extracellular 지질분해효소 생산을 향상시키기 위한 새로운 방법에 초점을 맞추었다. AR1 균주는 $35{\sim}75^{\circ}C$의 넓은 온도 범위에서 생육하였고 최적온도는 $65^{\circ}C$이었다. 생육을 위한 최적 pH는 6.5인 반면, 효소 생산을 위한 pH는 8.5로 차이점을 보였다. 배양 중에 지질 화합물의 첨가는 지질분해효소 생산을 유도하였고, soybean oil을 대수증식기에 첨가 했을 때 가장 효율적인 유도 효과를 나타내었다. 한편, 계면활성제는 지질분해효소의 생산을 유도하고 세포 내외의 위치에 영향을 줄 수 있다. AR1 균주는 정지기에 Tween 20을 첨가할 경우, 효소의 세포 외 분비 효율이 크게 증가하였다. 이들 결과를 바탕으로 soybean oil과 Tween 20을 각각 대수증식기와 정지기에 첨가함에 따라 extracellular 효소 생산이 대조구에 비해 2.4배 증가하는 것으로 확인 되었다.

• 대한화장품학회지
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• 제26권1호
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• pp.81-92
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• 2000

Development of stabilized enzyme was attempted for cosmetic applications. Papain, a proteolytic enzyme, was stabilized through conjugation with a soluble carbohydrate biopolymer, SC-glucan$^{TM}$ . With a novel structure of the conjugation site, stability of the enzyme was significantly enhanced such that more than 90% of the initial activity retained after a month storage at 45$^{\circ}C$, while no activity were detected in native enzyme or enzyme simply mixed with SC-glucan$^{TM}$ after the storage. Conjugation with SC-glucan$^{TM}$ not only extended the half-life of the enzyme on storage at higher temperature, but was also found to protect enzymes against some components contained in cosmetic products for skin care. Cosmetic lotion containing 1 % papain conjugate was more effective and less irritative in exfoliating stratum corneum of human skin than the lotion containing 5% lactic acid, one of the current popular exfoliating agents.gents.

• 한국미생물·생명공학회지
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• 제20권5호
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• pp.505-510
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• 1992

고온성 혐기성 세균인 Clostridium thermocellum의 섬유소 분해 효소 유전자를 pUC9 플라스미드를 이용하여 대장균에 클로닝하였고, 지금까지 클로닝 된 C.thermocellum의 섬유소 분해 유전자들과 제한효소 양상을 비교하여 새로운 유전자임을 알 수 있었다. 대장균에서 섬유소 분해 효소를 열처리와 column chromatography에 의해서 정제를 하였고, 분자량은 40, 000이었다. 이 효소는 pH 5.0과 $65^{\circ}C$에서 CMC에 대해서 최대 활성을 보였고 최종 산물인 포도당과 cellobiose에 의한 활성의 저해는 크게 나타나지 않았다. CMC에 대한 이 효소의 $K_{m}$ 과 $V_{max}$값은 각각 0.39(w/v)와 268 U/mg protein이었다.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1501-1509
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• 2012

A novel bacterial strain, MG7, with high cellulase activity was isolated and identified by morphological characteristics and molecular phylogeny analysis as Paenibacillus barcinonensis. Maximum production of cellulase by MG7 was observed at pH 7.0 and $35^{\circ}C$. The enzyme was purified with a specific activity of 16.88 U/mg, the cellulase activity was observed in a zymogram, and its molecular mass (58.6 kDa) was confirmed by SDS-PAGE. The purified enzyme showed maximum activity at pH 6.0 and $65^{\circ}C$ and degraded cellulosic substrates such as carboxy methyl cellulose (CMC), Avicel, filter paper, and ${\beta}$-glucan. The enzyme showed stability with 0.5% concentration of various surfactants. The $K_m$ and $V_{max}$ of cellulase for CMC and Avicel were found to be 0.459mg/ml and 10.46mg/ml/h, and 1.01 mg/ml and 10.0 mg/ml/h, respectively. The high catalytic activity and its stability to temperature, pH, surfactants, and metal ions indicated that the cellulase enzyme by MG7 is a good candidate for biotechnological applications.

• BMB Reports
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• 제34권4호
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• pp.347-354
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• 2001

$\alpha$-Glucosidase of an extreme thermophile, Thermus caldophilus GK24 (TcaAG), was purified 80-fold from cells to a homogeneous state and characterized. The enzyme exhibited optimum activity at pH 6.5 and $90^{\circ}C$, and was stable from pH 6.0 to 85 and up to $90^{\circ}C$. The enzyme had a half-life of 85 minutes at $90^{\circ}C$. An analysis of the substrate specificity showed that the enzyme hydrolyzed the non-reducing terminal unit of $\alpha$-1,6-glucosidic linkages of isomaltosaccharides and panose, $\alpha$-1,3-glycosidic bond of nigerose and turanose, and $\alpha$-1,2-glycosidic bond of sucrose. The gene encoding the TcaAG was cloned, sequenced, and sequenced in E. coli. The nucleotide sequence of the gene encoded a 530 amino acid polypeptide and had a G+C content of 68.4% with a strong bias for G or C in the third position of the codons (93.6%). A sequence analysis revealed that TcaAG belonged to the $\alpha$-amylase family. We suggest that this monomeric, thermostable, and broad-acting $\alpha$-glucosidase is a departure from previously exhibited specificities. It is, therefore, a novel $\alpha$-glucosidase.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.995-1000
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• 2010

A novel deoC gene was identified from Paenibacillus sp. EA001 isolated from soil. The gene had an open reading frame (ORF) of 663 base pairs encoding a protein of 220 amino acids with a molecular mass of 24.5 kDa. The amino acid sequence was 79% identical to that of deoxyribose 5-phosphate aldolase (DERA) from Geobacillus sp. Y412MC10. The deoC gene encoding DERA was cloned into an expression vector and the protein was expressed in Escherichia coli. The recombinant DERA was purified using Ni-NTA affinity chromatography and then characterized. The optimum temperature and pH of the enzyme were $50^{\circ}C$ and 6.0, respectively. The specific activity for the substrate deoxyribose 5-phosphate (DR5P) was $62\;{\mu}mol/min/mg$. The $K_m$ value for DR5P was determined to be 145 mM with the $k_{cat}$ value of $3.2{\times}10^2/s$ from Lineweaver-Burk plots. The EA001 DERA showed stability toward a high concentration of acetaldehyde (100 mM).