• 한국식품영양학회지
• /
• 제14권1호
• /
• pp.65-68
• /
• 2001

Bacillus sp. DSNC 101의 배양 상징액으로부터 $\alpha$-L-arabinofuranosidase를 정제하여 그 특성을 조사하였다. 정제된 효소의 분자량을 SDS-PAGE를 이용하여 측정한 결과 56kDa로 나타났으며 효소 활성도에 대한 최적 온도와 최적 pH는 각각 55$^{\circ}C$와 7.0이었다. p-nitrophenyl-alpha-L-arabinofuranoside에 대한 Km 값과 Vmax는 1.0mM과 113.6U/mg이었으며 Hg$^{2+}$과 Cu$^{2+}$의 첨가는 효소 반응을 완전히 저해하였다. Ba-cillus sp. DSNC 101은 탄소원으로 볏짚을 사용할 때 $\alpha$-L-arabinofuranosidase를 생산하였으나 xylan이나 glucose, cellulose를 탄소원으로 배양할 때는 생산되지 않았다.

• 한국연초학회지
• /
• 제23권2호
• /
• pp.103-108
• /
• 2001

Hog cholera virus(HCV) was purified from virus infected Bovine kidney cells. From this virus, total protein was analyzed by SDS-PAGE gel electrophoresis and about 55 kDa band of E2 envelope protein was detected. The viral RNA was purified and E2 cDNA was amplified by RT-PCR. E2 cDNA fragment was cloned to PCRII-TOPO cloning vector and named pE2. The analysis of nucleotide sequence showed that this E2 cDNA fragment inserted into pE2 was 1191 nucleotides long and coded 397 amino acids.

• BMB Reports
• /
• 제45권1호
• /
• pp.14-19
• /
• 2012

A feruloyl esterase encoding gene (designated fae6), derived from a leachate metagenomic library, was cloned and the nucleotide sequence of the insert DNA determined. Translational analysis revealed that fae6 consists of a 515 amino acid poly-peptide, encoding a 55 kDa pre-protein. The Fae6 primary structure contained the G-E-S-A-G sequence, which corresponds well with a typical catalytic serine sequence motif (G-x-S-x-G). The fae6 gene was successfully over-expressed in E. coli and the recombinant protein was purified to 8.4 fold enrichment with 17% recovery. The $K_M$ data showed Fae6 has a high affinity to methyl sinapate while thermostability data indicated that fae6 was thermolabile with a half life ($T_{1/2}$) < 30 min at $50^{\circ}C$. High affinity for Fae6 against methyl sinapate, methyl ferulate and ethyl ferulate suggest that the enzyme can be useful in hydrolyzing ferulated polysaccharides in a biorefinery process.

• 생명과학회지
• /
• 제22권7호
• /
• pp.912-919
• /
• 2012

Carboxymethylcellulose (CM-cellulose)와 Beechwood xylan을 각각 기질로 사용하여 trypan blue를 첨가하여 제작한 Agar-LB 배지 상에서 명확한 활성환을 형성하는 균주를 cellulase와 xylanase 생산 균주로 단리하였다. 단리한 균주 유래의 16S rRNA 유전자 및 API 50 kit를 분석한 결과 Bacillus subtilis와 약 99.5%의 높은 상동성을 보였기에 본 균주를 Bacillus subtilis로 동정하여 B. subtilis NC1로 명명하였다. B. subtilis NC1 유래 cellulase와 xylanase는 CM-cellulose와 Beechwood xylan에 대하여 각각 높은 효소 활성을 보였으며, 두 효소 모두 pH 5.0과 $50^{\circ}C$의 조건하에서 가장 높은 효소 활성을 보였다. B. subtilis NC1 균주 유래 cellulase와 xylanase 유전자를 cloning하기 위하여 shot-gun cloning 방법을 이용하여 B. subtilis NC1 염색체 DNA로부터 효소 유전자를 cloning하여 유전자 배열을 규명한 결과 cellulase 유전자는 아미노산 499개를 암호화하는 1,500 bp의 open reading frame (ORF)으로 이루어져 있었으며, 아미노산 배열로부터 추정되는 분자량은 55,251 Da 이었다. 그리고, xylanase에 대한 유전자는 아미노산 422개를 암호화하는 1,269 bp의 ORF로 이루어져 있었으며 유전자 유래 아미노산 배열로부터 추정되는 단백질 분자량은 47,423 Da 이었다. 두 효소의 아미노산 배열을 이용하여 상동성을 검토한 결과 cellulase는 glycoside hydrolase family (GH) 5에 속하는 cellulase와 xylanase는 GH30에 속하는 xylanase와 높은 상동성을 나타내었다.

• Journal of Applied Biological Chemistry
• /
• 제55권4호
• /
• pp.263-266
• /
• 2012

면실박으로부터 단백질을 추출한 후 단백질 가수분해효소인 Flavourzyme으로 가수분해를 실시하여 면실박 단백질 가수분해물을 얻었고, 가수분해 정도는 trinitrobenzenesulfonic acid 방법과 Sodium dodecyl sulfate-polyacrylamide gel electrophoresis를 통해 측정하였다. 면실박 단백질 가수분해물은 한외여과에 의하여 3 kDa 이하로 cut-off하였고, Q-Sepharos fast flow, Sephadex G-15, reversed-phase high performance liquid chromatography를 이용하여 Fe, Ca-binding 펩타이드를 분리하였다. 그 결과 철분과 칼슘 결합력이 가장 높은 분획 51을 얻을 수 있었고, 이렇게 얻어진 Fe, Ca-binding 펩타이드는 향후 기능성 식품 소재로써 활용될 수 있다고 판단된다.

• 한국잠사학회:학술대회논문집
• /
• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
• /
• pp.45-45
• /
• 2003

Protein disulfide isomerase (PDO) is an essential protein which is localized to the endoplasmic reticulum (ER) of eukaryotic cells. It catalyses the formation and isomerization of disulfide bonds during the folding of secretory proteins. We have isolarted a cDNA encoding PDI from Bombyx mori (bPDI), in which an open reading frame of 494 mino acid (55.6kDa) is shown. (omitted)

• 약학회지
• /
• 제55권4호
• /
• pp.301-308
• /
• 2011

Diabetes has been one of major health risks in industrialized countries. AMP-activated protein kinase (AMPK) has been focused as a novel therapeutic target for the treatment of metabolic syndromes, because AMPK increases glucose uptake through independent insulin signal pathway. In this study, we investigated the anti-diabetic effect of Angelica gigas Nakai extract (AGNEX), a mixture of decursin and decursinol angelate (53 : 47), decursin and decursinol angelate on blood glucose, glucose transport (GLUT) and AMPK expression levels in streptozotocin (STZ)-induced diabetic rats. To induce diabetes, 50 mg/kg of STZ was injected via i.v. route and AGNEX 2 mg/kg (STZ+AG), decursin 2 mg/kg (STZ+D), decursinol angelate 2 mg/kg (STZ+DA), and metformin 100 mg/kg (STZ+M) were administered orally for 21 days. STZ+DA group showed a significant decrease in fasting blood glucose levels compared to the other groups. Decursinol angelate significantly upregulated expression of glucose transporter 4 (GLUT4) and phosphorylation of AMPK (p-AMPK) in skeletal muscle of rats. In pancreas of rats, decursinol angelate significantly increased expression of GLUT2 through down-regulation of p-AMPK. In addition to the result of pancreatic islets morphology, AGNEX, decursin, decursinol angelate, and metformin treated group recovered ${\beta}$-cell damage by hyperglycemia. These results indicate that decursinol angelate might be a potential anti-diabetic agent and AGNEX could be useful in the treatment of diabetes mellitus.

• 한국식물병리학회지
• /
• 제10권3호
• /
• pp.215-221
• /
• 1994

Polygalacturonase (PG) produced by Botrytis cinerea in the culture broth containing citrus pectin as a carbon source was partially purified and characterized. PG was produced on a range of carbon sources such as starch, glycerol, cellobiose, and Na+-PAG with total activities of 34.8, 32.0, 29.2, 27.8 units, respectively. The specific activity was highest with 2316.7 units on Na+-PGA. Proteins of culture filtrate were concentrated with polyethylene glycol and acetone and applied to a hydroxyapatite column. Among three active fractions collected from the column, the reaction containing the highest PG activity was resolved by a Q-sepharose column. The active fraction from the Q-sepharose column was further purified by HPLC Mono Q column. The partially purified enzyme was analyzed by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Among a few protein bands revealed, the amount of the protein of which molecular weight estimated to be 43 kDa coincided with the PG activity. The partially purified PG had optimal temperatures between 35~55$^{\circ}C$ and pH between 4.5~5.5.

• BMB Reports
• /
• 제39권1호
• /
• pp.46-54
• /
• 2006

The coenzyme A-acylating 2-oxoacid:ferredoxin oxidoreductase and ferredoxin (an effective electron acceptor) were purified from the hyperthermophilic archaeon, Sulfolobus solfataricus P1 (DSM1616). The purified ferredoxin is a monomeric protein with an apparent molecular mass of approximately 11 kDa by SDS-PAGE and of $11,180{\pm}50$ Da by MALDI-TOF mass spectrometry. Ferredoxin was identified to be a dicluster, [3Fe-4S][4Fe-4S], type ferredoxin by spectrophotometric and EPR studies, and appeared to be zinc-containing based on the shared homology of its N-terminal sequence with those of known zinc-containing ferredoxins. On the other hand, the purified 2-oxoacid: ferredoxin oxidoreductase was found to be a heterodimeric enzyme consisting of 69 kDa $\alpha$ and 34 kDa $\beta$ subunits by SDS-PAGE and MALDI-TOF mass spectrometry. The purified enzyme showed a specific activity of 52.6 units/mg for the reduction of cytochrome c with 2-oxoglutarate as substrate at $55^{\circ}C$, pH 7.0. Maximum activity was observed at $70^{\circ}C$ and the optimum pH for enzymatic activity was 7.0 -8.0. The enzyme displays broad substrate specificity toward 2-oxoacids, such as pyruvate, 2-oxobutyrate, and 2-oxoglutarate. Among the 2-oxoacids tested (pyruvate, 2-oxobutyrate, and 2-oxoglutarate), 2-oxoglutarate was found to be the best substrate with $K_m$ and $k_{cat}$ values of $163\;{\mu}M$ and $452\;min^{-1}$, respectively. These results provide useful information for structural studies on these two proteins and for studies on the mechanism of electron transfer between the two.

• Journal of Microbiology and Biotechnology
• /
• 제19권10호
• /
• pp.1184-1190
• /
• 2009

A thermostable extracellular $\beta$-mannanase from the culture supernatant of a fungus Aspergillus niger gr was purified to homogeneity. SDS-PAGE of the purified enzyme showed a single protein band of molecular mass 66 kDa. The $\beta$-mannanase exhibited optimum catalytic activity at pH 5.5 and $55^{\circ}C$. It was thermostable at $55^{\circ}C$, and retained 50% activity after 6 h at $55^{\circ}C$. The enzyme was stable at a pH range of 3.0 to 7.0. The metal ions $Hg^{2+}$, $Cu^{2+}$, and $Ag^{2+}$ inhibited complete enzyme activity. The inhibitors tested, EDTA, PMSF, and 1,10-phenanthroline, did not inhibit the enzyme activity. N-Bromosuccinimide completely inhibited enzyme activity. The relative substrate specificity of enzyme towards the various mannans is in the order of locust bean gum>guar gum>copra mannan, with $K_m$ of 0.11, 0.28, and 0.33 mg/ml, respectively. Since the enzyme is active over a wide range of pH and temperature, it could find potential use in the food-processing industry.