• 한국미생물·생명공학회지
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• 제18권5호
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• pp.476-483
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• 1990

Hydantoinase(EC3.5.2.2) 생산을 위해 토양에서 분리한 균주 Y -183을 배양시킨 결과 Glycerol이 탄소원으로 양호했으며, 질소원으로는 혼합된 형태의 질소원이 요구되었다. 특히 Yeast ext.와 Beef ext.가 효소생성에 크게 영향을 미쳤고, Hydantoin 유도체 및 Pyrimidine 유도체의 영향을 조사한 결과 Uracil이 가장 양호한 결과를 나타냈다. 배양시간은 방선균의 특성상 72시간의 배양이 필요했으며 효소의 생성은 24시간 이후에 왕성하였다. 생성된 Hydantoinase는 균체내에 효소를 축적했으며 이들은 추출하여 기질로서 PL-5-phenylhydantion 등과 반응시킨 결과 N-carbamyl-D-amino acids가 생산되는 것이 분석결과 확인되었다.

• 한국축산식품학회지
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• 제33권5호
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• pp.565-571
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• 2013

An enzyme ${\beta}$-galactosidase or ${\beta}$-galactohydrolase [EC3.2.1.23], commonly called lactase, mediates galacto-oligosaccharide (GOS) synthesis under conditions of high substrate concentrations. Also, lactase hydrolyzes ${\beta}$($1{\rightarrow}4$) lactose into glucose and galactose, the latter is successively transferred to free lactose to make various oligosaccharides via transgalactosylation. GOS is non-digestible to human digestive enzymes and has been used as a functional prebiotics. Among the 24 lactic acid bacteria (LAB) strains used, Lactobacillus paracasei YSM0308 was selected based on its exhibition of the highest ${\beta}$-galactoside hydrolysis activity, and the crude lactase was prepared for examination of reaction conditions to affect the GOS synthesis. Lactase activity was measured with a spectrophotometer using ONPG (o-nitropheyl ${\beta}$-D-galactopyranoside) method. Lactase activity was not detected in the culture supernatant and was mostly present in the cell pellet after centrifugation. Activity of the crude lactase preparation ranges from102 to 1,053 units/mL, with the highest activity determined for L. paracasei YSM0308. Optimal conditions for GOS synthesis are as follows: concentration of whey powder, pH, temperature, and time were 30%, pH 6.5-7.0, $30^{\circ}C$, and 4 h, respectively. The final GOS concentration was 19.41% (w/v) by the crude YSM0308 lactase, which was obtained from strain YSM0308 grown in the 10% (w/v) reconstituted whey-based medium.

• ALGAE
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• 제30권3호
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• pp.241-246
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• 2015

This research was conducted to develop effective and safe marine-derived antiviral compounds against norovirus. The ethyl acetate (EtOAc)-extract from Eisenia bicyclis exhibited strong antiviral activity against murine norovirus (MNV) as a norovirus surrogate. Among the phlorotannins from E. bicyclis, dieckol (DE) and phlorofucofuroeckol-A (PFF) were known to possess the strongest antibacterial activity. In this study, DE and PFF were evaluated for antiviral activity against MNV. DE and PFF exhibited strong anti-MNV activity with 50% effective concentration ($EC_{50}$) of $0.9{\mu}M$. However, PFF exhibited more effective antiviral activity against MNV with higher selective index (668.87) than that of DE (550.60), due to its lower cell toxicity against RAW 264.7. This is the first report on the anti-MNV activity of phlorotannins from seaweed. The results obtained in this study suggest that the phlorotannins could be used as a potential source of natural antiviral agents.

• 한국미생물·생명공학회지
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• 제13권1호
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• pp.19-25
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• 1985

Saccharomyces cerevisiae HIS 5 유전자는 histidinol phosphate aminotransferase (EC: 2, 6, 1,9)를 code하는 아미노산 합성유전자이다. 이 유전자는 plasmid pSH 530에 cloning되어 E. coli와 Saccharomyces cerevisiae 숙주에서 promoter로서 전사하였다. HIS 5 유전자의 총염기 수는 736개이였고 5' 상류영역에는 긴 reading frame, directed repeat, 전사개시점, 그리고 Pribnow box염기배열이 있었다. 특히 HIS 5 유전자의 ATG 주변 염기배열은 -A-A-A-T-T-A-C-A-C-T-A-T-G-G-T-T-T-T-T-G-A-T-였으며 C block은 없었다.

• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.91-96
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• 1997

Lipocortin 1 has been proposed as a putative mediator of anti-inflammatory actions of glucocorticoids. We investigated the role of lipocortin 1 in the effect of dexamethasone using rat splenic leukocytes. Concanavalin A(ConA; 1 ${\mu}g/ml$) increased the leukocyte proliferation and nitric oxide(NO) generation, which were measured as $[^3H]-thymidine$ uptake by the cells and nitrite accumulation in the culture media, respectively. Dexamethasone suppressed ConA-induced cell proliferation, in a concentration-dependent manner with $EC_{50}$ around 50nM. The addition of anti-lipocortin l(Anti-LCl) reversed dexamethasone effects: 0.24, 1.2, 6 ${\mu}g/ml$ of Anti-LC1 reversed dexamethasone(50 nM)-induced suppression of thymidine uptake by $9{\pm}3%$, $16{\pm}3%$, $36{\pm}5%$, respectively; 0.24, 1.2, and 6 ${\mu}g/ml$ of Anti-LCI reversed dexa-methasone-induced decrease of nitrite concentration by $49{\pm}16%$, $61{\pm}20%$, $77{\pm}19%$, respectively. The present data indicate that lipocortin 1 mediates, at least in part, glucocorticoids-induced suppression of leukocyte proliferation and blockade of NO generation.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1047-1053
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• 2005

Cyclosporin A binding protein type-19 kDa peptidyl-prolyl cis/trans isomerase (PPIases, EC 5.2.1.8) of Euglena gracilis was purified and some of its biochemical characters were elucidated. Purification of the PPIase was achieved by employing a series of steps involving ammonium sulfate precipitation, Superdex G-75 gel filtration chromatography, Mono­Q anion and Mono-S cation exchange chromatographies, and Superdex S-200 gel filtration chromatography on FPLC. Purified PPIase had a specific activity of 8,250 units/mg, showing a 27-fold increase compared with that of cell-free extract of Euglena gracilis. The enzyme consisted of a single polypeptide chain with a molecular mass of 19 kDa. It showed high substrate specificity to succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, and $k_{car}/K_{m}$, for this substrate was found to be $61.19{\times}10^5/sec$. The isomer distributions were investigated at an equilibrium of seven different peptide substrates, varying Xaa in Suc-Ala-Xaa-Pro-Phe-p-nitroanilide in dimethylsulfoxide. The cis/trans equilibrium constants were estimated to be from 0.14 (Ile) to 0.63 (Gly), which correspond to $12.00\%\;to\;38.52\%$ of the cis population, respectively, under experimental condition. The enzyme was highly sensitive to the immunosuppressive ligand cyclosporin A, but not to other immunosuppressants such as FK506 and rapamycin. Thus, it appears to belong to the class of cyclophilin.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.572-578
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• 2016

Communication between endothelial cells (ECs) and smooth muscle cells (SMCs) via miR-143/145 clusters is vital to vascular stability. Previous research demonstrates that miR-143/145 released from ECs can regulate SMC proliferation and migration. In addition, a recent study has found that SMCs also have the capability of manipulating EC function via miR-143/145. In the present study, we artificially increased the expression of miR-143/145 in ECs, to mimic a similar change caused by miR-143/145 released by SMCs, and applied untargeted metabolomics analysis, aimed at investigating the consequential effect of miR-143/145 overexpression. Our results showed that miR-143/145 overexpression alters the levels of metabolites involved in energy production, DNA methylation, and oxidative stress. These changed metabolites indicate that metabolic pathways, such as the SAM cycle and TCA cycle, exhibit significant differences from the norm with miR-143/145 overexpression.

• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.37-42
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• 2013

Taxifolin glycoside is a new drug candidate for the treatment of atopic dermatitis (AD). Many drugs cause side effects such as long QT syndrome by blocking the human ether-a-go-go related gene (hERG) $K^+$ channels. To determine whether taxifolin glycoside would block hERG $K^+$ channels, we recorded hERG $K^+$ currents using a whole-cell patch clamp technique. We found that taxifolin glycoside directly blocked hERG $K^+$ current in a concentration-dependent manner ($EC_{50}=9.6{\pm}0.7{\mu}M$). The activation curve of hERG $K^+$ channels was negatively shifted by taxifolin glycoside. In addition, taxifolin glycoside accelerated the activation time constant and reduced the onset of the inactivation time constant. These results suggest that taxifolin glycoside blocks hERG $K^+$ channels that function by facilitating activation and inactivation process.

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.93-99
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• 2002

Effects of oxidized low-density lipoprotein (ox-LDL), $1-{\alpha}-stearoyl-lysophosphatidylcholine$ (LPC), on intracellular $Ca^{2+}$ concentration were examined in mouse endothelial cells by measuring intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ with fura 2-AM and reverse transcription-polymerase chain reaction (RT-PCR). LPC increased $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o$ but did not show any effect under the nominally $Ca^{2+}-free$ condition. Even after the store depletion with $30{\mu}M$ 2,5-di-tert- butylhydroquinone (BHQ) or $30{\mu}M$ ATP, LPC could still increase the $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o.$ The time required to increase [$Ca{2+}$]i (about 1 minute) was longer than that for ATP-induced $[Ca^{2+}]_i$ increase $(10{\sim}30\;seconds).$ LPC-induced $[Ca^{2+}]_i$ increase was completely blocked by $1{\mu}M\;La^{3+}.$ Transient receptor potential channel(trpc) 4 mRNA was detected with RT-PCR. From these results, we suggest that LPC increased $[Ca^{2+}]_i$ via the increase of $Ca^{2+}$ influx through the $Ca^{2+}$ routes which exist in the plasma membrane.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.827-830
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• 2013

Investigation of an organic extract of the fruits Schisandra wilsoniana led to the isolation of two new highly oxygenated nortriterpenoids, named schilancidilactones V-W (1-2). Their structures were elucidated by spectroscopic evidence. Compounds 1-2 feature a double bond between C-7 and C-8 compared with related known nortriterpenoids isolated from the genus Schisandra. Compounds 1 and 2 were tested for their anti-HIV-1 activities and cytotoxicity. The results revealed that compounds 1 and 2 showed moderate anti-HIV-1 activities with $EC_{50}$ 3.05 and 2.87 ${\mu}g/mL$, respectively, and compound 1 showed high cytotoxicity against KB and MDA-MB-231 cell with $IC_{50}$ values of 3.18 and 5.22 ${\mu}M$, respectively.