• Microbiology and Biotechnology Letters
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• 제40권1호
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• pp.17-22
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• 2012

A bacterial strain was isolated from homemade Cheongkookjang as a producer of the ${\beta}$-galactosidase, capable of hydrolyzing lactose to liberate galactose and glucose residues. The isolate YB-1105 has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. ${\beta}$-Galactosidase activity was detected in both the culture supernatant and the cell extract of B. licheniformis YB-1105. The enzymes of both fractions demonstrated maximum activity for hydrolysis of para-nitrophenyl-${\beta}$-D-galactopyranoside (pNP-${\beta}Gal$) under identical reaction conditions of pH 6.5 and $50^{\circ}C$. However, ${\beta}$-galactosidase activity from the culture filtrate was affected more than that from the cell free extract at acidic pHs and high temperatures. The hydrolyzing activity of both ${\beta}$-galactosidases for pNP-${\beta}Gal$ was dramatically decreased by the addition of low concentrations of galactose, but was only marginally decreased by high concentrations of glucose or mannose.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.239-248
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• 2017

Desensitization and acute tolerance are terms used to describe the attenuation of receptor responsiveness by prolonged or intermittent exposure to an agonist. Unlike desensitization of G protein-coupled receptors (GPCRs), which is commonly explained by steric hindrance caused by the ${\beta}$-arrestins that are translocated to the activated receptors, molecular mechanisms involved in the acute tolerance of GPCRs remain unclear. Our studies with several GPCRs and related mutants showed that the acute tolerance of GPCRs could occur independently of agonist-induced ${\beta}$-arrestin translocation. A series of co-immunoprecipitation experiments revealed a correlation between receptor tolerance and interactions among receptors, ${\beta}$-arrestin2, and $G{\beta}{\gamma}$. $G{\beta}{\gamma}$ displayed a stable interaction with receptors and ${\beta}$-arrestin2 in cells expressing GPCRs that were prone to undergo tolerance compared to the GPCRs that were resistant to acute tolerance. Strengthening the interaction between $G{\beta}{\gamma}$ and ${\beta}$-arrestin rendered the GPCRs to acquire the tendency of acute tolerance. Overall, stable interaction between the receptor and $G{\beta}{\gamma}$ complex is required for the formation of a complex with ${\beta}$-arrestin, and determines the potential of a particular GPCR to undergo acute tolerance. Rather than turning off the signal, ${\beta}$-arrestins seem to contribute on continuous signaling when they are in the context of complex with receptor and $G{\beta}{\gamma}$.

• Journal of Life Science
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• 제21권10호
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• pp.1494-1499
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• 2011

${\beta}$-lapachone, a quinone of lapachol extracted from the bark of the lapacho tree, has been found to induce apoptosis in various human cancer cells. In the present study, we investigated further possible mechanisms by which ${\beta}$-lapachone exerts its pro-apoptotic action in cultured human lung cancer A549 cells. ${\beta}$-lapachone treatment resulted in inhibition of growth and induction of apoptosis in a concentration-dependent manner, as determined by MTT assay and flow cytometry analysis. The induction of apoptosis by ${\beta}$-lapachone was associated with up-regulation of the expression of p53 and p21 in both transcriptional and translational levels, and the phosphorylation of p53. In addition, ${\beta}$-lapachone activated caspase-3 and -9, and induced degradation of caspase-3 target proteins such as poly (ADP-ribose) polymerase (PARP) and ${\beta}$-catenin. Furthermore, ${\beta}$-lapachone treatment caused a progressive decrease in the expression levels of cyclooxygenase (COX)-2 without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E2 synthesis. Taken together, these results indicated that ${\beta}$-lapachone may have therapeutic potential in human lung cancer treatment.

• Journal of Life Science
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• 제17권9호통권89호
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• pp.1298-1302
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• 2007

A hallmark of cancers is 'leaky' tight junctions (Tjs). TJs mediated paracellular permeability is elevated and TJs maintained cell polarity is frequently lost. Concomitantly, TJs-associated proteins including members of the claudin family of proteins are dysregulated. Recent findings indicate that these TJs changes can contribute to cancer progression. In this study, we examined the effects of ${\beta}-lapachone$, a quinone compound obtained from the bark of the lapacho tree (Tabebuia avellanedae), on the Tjs-associated regulators in human hepatocarcinoma cell lines, HepG2 and Hep3B. ${\beta}-lapachone$ treatment downregulated the levels of insulin-like growth factor 1 receptor (IGF-lR) proteins in both HepG2 and Hep3B cells. But the levels of claudin-3 and -4 proteins were increased in ${\beta}-lapachone$-treated HepG2 and Hep3B cells. And also the zonnula occludens-l (la-I) and p-catenin protein levels by ${\beta}-lapachone$ were increased in a time-dependent manner. However, claudin-3 and -4 mRNA levels were uninhibited by ${\beta}-lapachone$ in HepG2 and Hep3B. The present results suggest that the upregulation of claudin-3 and -4 protein levels by ${\beta}-lapachone$ occurs by a post-transcriptional mechanism and points to a novel mechanism by ${\beta}-lapachone$.

• Applied Biological Chemistry
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• 제42권4호
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• pp.324-329
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• 1999

Barley malts were prepared at 15, 18 and $21^{\circ}C$ for $3{\sim}6$ days, and assayed for ${\beta}-glucanase$, ${\alpha}-amylase$ and ${\beta}-amylase$ activities. ${\beta}-Glucanase$ activity increased markedly during earley germination and reached maximum at the 6th day of germination. ${\beta}-Glucanase$ activity in six-rowed barley malt was much higher than that in two-rowed malt. ${\beta}-Glucanase$ activity was associated with reduction in ${\beta}-glucan$ content during germination. ${\beta}-amylase$ activity was also considerably higher in two-rowed barley, and increased continuously during 6-day germination. ${\beta}-Amylase$ activity was the lowest at $15^{\circ}C$, the highest at $18^{\circ}C$, and intermediate at $21^{\circ}C$ of germination temperature. Considerable amount of ${\beta}-amylase$ was detected in ungerminated raw barley, and this enzymatic activity tended to increase during 6-day germination. Diastatic power, measure of starch-saccharifying enzyme, in six-rowed malt was $1.4{\sim}1.6$ fold higher than in two-rowed malt. Germination at $18^{\circ}C$ for $5{\sim}6$ days was suggested to be the optimum condition for manufacturing good quality malts, in terms of enhanced starch-degrading enzymatic activity.

• Korean Journal of Animal Reproduction
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• 제22권1호
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• pp.73-80
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• 1998

This study was undertaken to evaluate the interaction between cumulus cells and TGF $\beta$1 on in vitro maturation in porcine oocytes. No differ ences were found in maturation rates when follicular oocytes were cultured in medium with various concentrations of TGF $\beta$. At 24 h after maturation, the oocytes matured to metaphase-II were found in medium with TGF $\beta$ regardless of cumulus cells. On the other hand, the maturation rates were significantly(P < 0.01 higher cumulus-enclosed(70 and 52%) than cumulus-denuded oocytes(35 and 26%) in medium with or without TGF $\beta$ at 48 h after culture. In a another experiment, the same maturation rates (54-71%) were observed when cumulus-enclosed oocytes were cultured with various addition time of TGF $\beta$. However, the maturation rates in cumulus-denuded oocytes were significantly (P < 0.05) higher in medium added at 0~24 h (59%) or 24-48 h(57%) after culture than in medium with(27%) and without(38%) TGF $\beta$ for 48 h. These results indicated that cumulus cells is essential for in vitro maturation in porcine oocytes but TGF $\beta$ can promote oocytes maturation in cumulus-free oocytes.

• The Korean Journal of Nuclear Medicine
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• 제30권1호
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• pp.19-34
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• 1996

[ $[^{123}I]{\beta}$ ]-CIT [$2{\beta}$-carbomethoxy-$3{\beta}$-(4-iodophenyl)tropane]는 도파민 운반체 (dopamine transporter)에 특이결합하며 $[^{123}I]{\beta}$-CIT의 도파민 운반체 결합정도는 파킨슨병에서 도파민 뉴우런의 변성정도를 반영하는 것으로 제안되어 왔다. 이 연구의 주요 목적은 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT SPECT를 이용하여 측정된 $[^{123}I]{\beta}$-CIT의 선조체 결합지표들이 질병의 임상적 진행정도를 반영하는지를 검토하고, 간편화된 조직방사능비가 $[^{123}I]{\beta}$-CIT의 결합정도를 나타내는 정량적 지표로 이용될 수 있는지를 검증하는 것이었다. 파킨슨병 환자 30명($59{\pm}9$세, 평균${\pm}$표준편차: Hoehn-Yahr stage 1-3)과 정상인 6명 ($58{\pm}5$세)을 대상으로 $[^{123}I]{\beta}$-CIT SPECT 영상을 얻었다. $[^{123}I]{\beta}$-CIT 선조체 결합의 정량적 지표로서 (선조체 방사능-소뇌방사능)/소뇌방사능 비(specific binding ratio, SBR)와 추적자역학모델을 이용하여 측정한 선조체 결합능(binding potential)($k_3/k_4$)을 구하였다. 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT의 선조체 결합역학은 정상인에 비하여 현저하게 느렸으며 그 결합지표들은 정상인에 비하여 뚜렷하게 낮았다. 한편, 편측파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT 결합은 증상 반대쪽 선조체 뿐만 아니라 같은 쪽 선조체에서도 정상인에 비해 유의하게 감소되어 있었다. 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT 투여 후 24시간의 선조체 SBR 및 최대 SBR, 선조체 결합능은 모두, 유병기간, Hoehn-Yahr stage, UPDRS(Unified Parkinson's Disease Rating Scale) 총점, UPDRS 운동점수, UPDRS 일상활동점수와 유의한 상관관계를 나타내었다. 24시간 선조체 SBR과 최대 SBR은 선조체 결합능과 우수한 상관관계를 보였다. 이상의 결과로부터 $[^{123}I]{\beta}$-CIT의 선조체 결합은 파킨슨병의 진행정도를 나타내는 지표로 이용될 수 있다. 또 $[^{123}I]{\beta}$-CIT 투여 후 24시간 영상으로부터 얻은 간편화된 조직방사능 비는 $[^{123}I]{\beta}$-CIT의 결합정도를 정량적으로 반영한다. $[^{123}I]{\beta}$-CIT SPECT는 파킨슨병의 조기진단 및 진행 추적에 임상적으로 유용할 것으로 판단된다.

• Microbiology and Biotechnology Letters
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• 제20권4호
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• pp.422-429
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• 1992

The effect of various water-activity depressors, such as pol yo Is, sugars, and polymers, on the conversion yields of the enzymatic synthesis of maltosyl-$\beta$-cyclodextrin from $\beta$-cyc1odextrin and maltose through reverse reaction of pullulanase was investigated. PEG 6000 of concentration of 10% (w/w) was found to be the most acceptable water-activity depressor resulting for increment of conversion yield from 43.0% to 55.9%, corresponding maltosyl-$\beta$-cyc1odextrin concentration of 3.02 g/100 ml H20. Water activity was changed from initial 0.966 to 0.914 upon addition of 20% (w/w) of PEG 6000. The conversion yields were inversely proportional to the water activities, and the increased conversion yield was caused by water activity depression which inhibited the hydrolysis reaction of maltosyl-$\beta$-CD to maltose and $\beta$-cyc1odextrin. The changes of enthalpy ($\Delta$H), entropy ($\Delta$S), and Gibbs free energy ($\Delta$G) were calculated to be 36.788 kJ/mole, 0.067 kJ/mole K. and 14.433 kJ/mole, respectively. The synthesis of maltosyl-$\beta$-CD could be increased substantially by the intermittent feeding of $\beta$-cyclodextrin. PEG 6000 could be separated effectively from reaction mixture using ultrafiltration membrane for reutilization.

• The Korean Journal of Malacology
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• 제31권2호
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• pp.123-127
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• 2015

${\beta}$-Glucan is a polysaccharide that is widely used as an adductive in fish feed to facilitate immune stimulation. This study aimed to investigate the effect of ${\beta}$-glucan on immune responses in the Manila clam Ruditapes philippinarum. For this purpose, three groups of R. philippinarum were exposed to 0%, 0.1%, or 1% ${\beta}$-glucan in sea water for 1 hr/day for 2 weeks using an immersion method. Thereafter, two immune parameters-phagocytic rate and antibacterial activity-were measured. R. philippinarum exposed to 1% ${\beta}$-glucan showed an approximate 30% significant increase in phagocytic rate. In addition, ${\beta}$-glucan significantly limited the growth of the pathogenic bacteria Vibrio tapetis, V. parahaemolyticus, and V. ordalii. Moreover, the mortality rates of ${\beta}$-glucan-treated clams decreased during a 17-day experiment. Our study suggests that treatment with ${\beta}$-glucan significantly increases the immune responses in R. philippinarum, and that immersion is a simple and effective method for immune stimulation in this species.

• Korean Journal of Food Science and Technology
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• 제35권4호
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• pp.610-616
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• 2003

Five oats and 17 barley cultivars were ground, sieved (105, 210, 300, 425, 600 ${\mu}m$) and we have analyzed the ${\beta}-glucan$ contents to obtain grain fractions. The milling yields ranged $65.1{\sim}89.7%$ for barley and $53.4{\sim}73.5%$ for oat cultivars. Total ${\beta}-glucan$ contents of barley and oats become higher than those of the flour increasing the particle size. The soluble and insoluble ${\beta}-glucan$ contents of them were especially higher in medium and coarse particle size fractions. The contents of total, soluble and insoluble ${\beta}-glucan$ of barley were 1.5, 1.7 and 2.0 times higher than the whole flour before sieving and these content of oats were 2.1, 1.6 and 2.0 times, respectively. In this study, larger particle size would enrich the ${\beta}-glucan$ and it is desirable to consider the best particle size range to enrich the ${\beta}-glucan$ level, the water-solubility of the ${\beta}-glucan$ as well as cereal varieties.