• Molecules and Cells
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• 제19권3호
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• pp.375-381
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• 2005

Phospholipase C-${\beta}$ (PLC-${\beta}$) hydrolyses phosphatidylinositol 4,5-bisphosphate and generates inositol 1,4,5-trisphosphate in response to activation of various G protein-coupled receptors (GPCRs). Using glial cells from knock-out mice lacking either PLC-${\beta}1$ [PLC-${\beta}1$ (-/-)] or PLC-${\beta}3$ [PLC-${\beta}3$ (-/-)], we examined which isotype of PLC-${\beta}$ participated in the cellular signaling events triggered by thrombin. Generation of inositol phosphates (IPs) was enhanced by thrombin in PLC-${\beta}1$ (-/-) cells, but was negligible in PLC-${\beta}3$ (-/-) cells. Expression of PLC-${\beta}3$ in PLC-${\beta}3$ (-/-) cells resulted in an increase in pertussis toxin (PTx)-sensitive IPs in response to thrombin as well as to PAR1-specific peptide, while expression of PLC-${\beta}1$ in PLC-${\beta}1$ (-/-) cells did not have any effect on IP generation. The thrombin-induced $[Ca^{2+}]_i$ increase was delayed and attenuated in PLC-${\beta}3$ (-/-) cells, but normal in PLC-${\beta}1$ (-/-) cells. Pertussis toxin evoked a delayed $[Ca^{2+}]_i$ increase in PLC-${\beta}3$ (-/-) cells as well as in PLC-${\beta}1$ (-/-) cells. These results suggest that activation of PLC-${\beta}3$ by pertussis toxin-sensitive G proteins is responsible for the transient $[Ca^{2+}]_i$ increase in response to thrombin, whereas the delayed $[Ca^{2+}]_i$ increase may be due to activation of some other PLC, such as PLC-${\beta}4$, acting via PTx-insensitive G proteins.

• 한국식품영양과학회지
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• 제40권8호
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• pp.1092-1098
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• 2011

본 연구에서는 당뇨병의 치료에 중요한 저해요인으로 제기되고 있는 당뇨합병증을 예방하고자 녹황색 채소 등을 통해 식사 시 한국인들이 쉽게 섭취할 수 있는 ${\beta}$-carotene의 혈관계 합병증 예방효과를 분석하고자 하였다. 간 미토콘드리아에서의 catalase 활성은 ${\beta}$-carotene을 급여한 비당뇨군에서 유의적으로 높은 활성을 나타내었으나 당뇨군에서는 ${\beta}$-carotene 급여에 의한 영향을 나타내지 않았다. 간 사이토졸 내의 superoxide dismutase 활성은 ${\beta}$-carotene을 급여하지 않은 당뇨군에서 그 활성이 가장 저하되었으나 ${\beta}$-carotene 공급에 의해 유의적으로 증가되었다. 간 사이토졸 내의 glutathione-S-transferase 활성은 ${\beta}$-carotene의 급여에 의한 차이가 없었다. 간 마이크로솜에서의 glucose-6-phosphatase 활성은 대조군에 비하여 ${\beta}$-carotene을 급여하지 않은 당뇨군에서 유의적으로 높게 나타났으나 ${\beta}$-carotene을 급여한 당뇨군에서는 활성이 유의적으로 저하되었다. 간조직의 환원형 glutathione 함량은 당뇨군에서 유의적으로 감소되었으며, 당뇨군에서 ${\beta}$-carotene의 급여로 증가하였다. 이상의 결과에서 볼 때 ${\beta}$-carotene의 섭취는 당뇨 유도에 의한 산화스트레스가 증가된 생리적 상태에서 glutathione의 소모를 감소시키고, 항산화 효소계 중 특히 superoxide dismutase 활성을 유도하여 과산화 라디칼을 환원시킴으로써 활성산소에 의해 유발되는 산화적 손상의 일차적 방어에 관여한 것으로 여겨진다. 따라서 인체시험 등을 통한 후속연구와 연계하여 ${\beta}$-carotene 수준을 적절하게 보충 섭취한다면 당뇨로 인한 항산화계 활성의 변화를 조절함으로써 산화스트레스에 대한 보호효과를 나타내어 당뇨병 합병증의 예방에 기여할 수 있을 것으로 여겨진다.

• Toxicological Research
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• 제27권4호
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.

• 한국식품조리과학회지
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• 제19권5호
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• pp.616-623
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• 2003

Bran(1∼5번)의 총 평균 $\beta$-glucan 함량은 5.52%로서 가장 높은 회수율 (48.5%)을 보인 추출 조건은 pH 10 및 45$^{\circ}C$, 다음은 pH 7 및 45$^{\circ}C$로 나타났다. 보리겨의 gum 물질은 배유 부분의 gum 물질과는 달리 상당량의 전분, 단백질이 혼입되어 있었고 정제된 $\beta$-glucan 도 단백질 및 전분 함량이 감소되긴 하였으나 호분층 안쪽의 bran 1,2,3,4에서도 $\beta$-glucan 함량이 78.2∼85.8%를 나타내어 세포벽의 peptide, arabinoxylan 등과 강하게 결합됨을 알 수 있었다. $\beta$-glucan을 이루는 구성당은 glucose가 주종이며, 그 외 arabinose, xylose, mannose, galactose였으며, 분자량은 보리겨에 따라 차이가 있으나 bran 1∼3의 경우 4.09 x $10^{5}$ 에서 4.41 x $10^{5}$ 정도의 분자량이 90% 이상을 차지하였으며, 다당 고유의 특성인 분자량의 분산성을 나타내었다. 한편 $\beta$-glucan의 구조 역시 보리겨에 따라 다소 차이가 있으나 $\beta$-(1\$\longrightarrow$3) 결합, $\beta$-(1\$\longrightarrow$4) 결합이 대부분을 차지하였고, $\beta$-glucan용액의 유동특성은 농도가 증가함에 따라 유동지수는 감소하여 의가소성이 증가하는 경향을 나타내었다.

• 한국미생물·생명공학회지
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• 제37권2호
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• pp.99-104
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• 2009

Streptomyces coelicolor A3(2)의 $\beta$-glucosidase 유전자를 분리하여 대장균에서 발현하여 특성을 조사하였다. 최적 활성을 나타내는 온도는 pH 5에서는 $20^{\circ}C$, pH 6에서는 $60^{\circ}C$에서 높은 활성을 나타냈다. pH에 따른 활성은 pH 3 이하와 pH 9 이상의 범위에서는 낮은 활성을 나타냈으며 pH 7에서 가장 높은 활성을 나타냈다. $\alpha$-pNPG($\rho$-nitrophenyl-$\alpha$-D-glucopyranoside), $\beta$-pNPG ($\rho$-nitrophenyl-$\beta$-D-glucopyranoside), $\beta$-pNPF($\\rho$-nitrophenyl-$\beta$-D-fucopyranoside)는 pH 3-10까지 비슷한 활성을 나타냈으며, $\alpha$-pNPG가 pH 7에서 다소 높은 활성을 보였다. $\beta$-pNPGA는 pH 5-9까지 높은 활성을 나타냈으며, 특히 pH 9에서 3배 이상의 높은 활성을 나타냈다. 기질 $\alpha$-pNPG, $\beta$-pNPG, $\beta$-pNPF의 온도에 따른 활성변화는 $\beta$-pNPF의 활성이 $60^{\circ}C$에서 증가하였고, $\beta$-pNPGA는 $30-50^{\circ}C$까지 활성이 증가하여 $50^{\circ}C$에서 최대활성을 나타내었다. 당화 flavonoid를 이용한 기질특이성의 상대활성은 daidzin, glycitin, genistin, 순으로 나타났으며 esculin과 apigenin-7-glucose는 기질로 사용하지 않았다. $\beta$-Glucosidase 활성은 EDTA, DTT에 의해 억제되었으며, $MnSO_4$, $CaCl_2$, KCl, $MgSO_4$에 의해 증가하였고, 특히 Mn이온에 의해 증가하였다. $CuSO_4$, NaCl에 의해 효소활성이 저해되었으며, 특히 $ZnSO_4$의 경우 효소활성이 강하게 억제되었다.

• 한국식품영양학회지
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• 제12권2호
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• pp.184-190
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• 1999

Soybean protein consists of two major components $\beta$-conglycinin and glycinin which together consti-tute 70% of the total seed storage protein at maturity. $\beta$-Conglycinin is trimeric glycoprotein and for-med by the assembly of various combinations of three subunits $\alpha$,$\alpha$' and $\beta$ which have molecular weig-hts of 69,000, 72,000 and 42,000, respectively. Recently $\beta$-conglycinin was identified as powerful LDL lip-oprotein receptor activation hypercholesterolemia and major allergenic proteins. To investigate these reasons we constructed an expression system of cDNA encoding $\alpha$-subunit of $\beta$-conglycinin in Escherichia coli and purified the expressed protein. The pro-$\beta$-conglycinin synthesized in Escherichia coli BL 21 (DE3)comprised approximately 15% of the total bacterial proteins and the expressed protein are formed sol-uble and trimer such as native protein in Escherichia coli cells. The highly expressed protein was purified to homogeneity by salt precipitation with 20~40 % ammonium sulfate ion-exchange chromatography with Q-sepharose and hydrophobic column chromatography with Butyltoyopearl.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.141-145
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• 1998

Overproduction of intracellular ${\beta}$-glucosidase was attempted by modifying the promoter region of a ${\beta}$-glucosidase gene cloned from Cellulomonas fimi and expressing it in Bacillus subtilis DB 104. A strong engineered promoter, BJ27UΔ88, was fused to the ${\beta}$-glucosidase gene after removing its native promoter. An effective Shine-Dalgamo sequence (genel0 of phage T7) was inserted between the promoter and the ${\beta}$-glucosidase structural gene. The modified gene was overexpressed in B. subtilis and produced 1121.5 units of ${\beta}$-glucosidase per mg protein which is about $12\%$ of total intracellular protein. Secretion of overproduced intracellular ${\beta}$-glucosidase was attempted by using the signal sequence of the Bacillus endoglucanase gene as well as an in-frame hybrid protein of endoglucanase. The hybrid protein was normally secreted into the culture medium and still retained ${\beta}$-glucosidase activity.

• 대한수학회논문집
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• 제20권1호
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• pp.23-34
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• 2005

Let R be a ring with left identity. Let G : $R{\times}R{\to}R$ be a symmetric biadditive mapping and g the trace of G. Let ${\alpha}\;:\;R{\to}R$ be an endomorphism and ${\beta}\;:\;R{\to}R$ an epimorphism. In this paper we show the following: (i) Let R be 2-torsion-free. If g is (${\alpha},{\beta}$)-skew-commuting on R, then we have G = 0. (ii) If g is (${\beta},{\beta}$)-skew-centralizing on R, then g is (${\beta},{\beta}$)-commuting on R. (iii) Let $n{\ge}2$. Let R be (n+1)!-torsion-free. If g is n-(${\alpha},{\beta}$)-skew-commuting on R, then we have G = 0. (iv) Let R be 6-torsion-free. If g is 2-(${\alpha},{\beta}$)-commuting on R, then g is (${\alpha},{\beta}$)-commuting on R.

• 한국진공학회지
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• 제4권2호
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• pp.224-229
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• 1995

쌍곡선 모델을 사용하여 미시 통로죔을 통과하는 2차원 전자들의 양자 탄동적 수송현상을 연구하였다. 통로죔은 타원좌표계($\alpha$, $\beta$)에서 $\beta$=$\beta$o, $\pi$-$\beta$o로 주어지는 두 쌍곡선으로 기술하였다. 양자화된 88컨덕턴스 G는 타원좌표계에서 주어진 슈뢰딩거 방정식과 쌍곡선 경계조건을 만족하는 짝 매튜 함수를 이용하여 계산하였다. 그 결과는 채널수 Nc는 통로죔 폭 W뿐만 아니라 곡률 관련좌표 $\beta$o에 의존함을 나타내었다. 또한 곡률에 의존하는 터널링도 양자화된 G의 그래프의 모양을 나타내는 중요한 요소임을 나타내 주었다. 고정된 통로폭에서 Nc가 일정한 $\beta$o영역에서는 $\beta$o의 연속적 변화에 G는 연속적으로 변화하였지만 $\beta$o가 크게 변화할 때는 Nc가 변화하여 G는 불연속적으로 변화하였다. 만일 터널링이 거의 허용이 안되는 $\beta$o의 영역에서는 G는 계단식의 변화만 보여주었다.

• 한국임상수의학회지
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• 제11권1호
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• pp.389-392
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• 1994

To purify transforming growth factor type beta(TGF-$\beta$) in canine platelets, Sephadex G-75 gel filtration and semipreparative HPLC were carried out. The column of $2.0 {\times}120cm$ was used for gel filtration and one inch semipreparative column filled with SP-Toyopeal for HPLC. Electrophoresis and bioassay using African green monkey kidney cell were used for identification of TGF-$\beta$ Crude TGF-$\beta$ of 2.75mg was extracted from 5.2g of the platelets by the treatment of acid/ethanol. In gel filtration of crude TGF-$\beta$, 4 peaks were observed at the detection of spectrophotometer at 280nm. Electrophoresis and bioassay identified the 3rd peak TGF-$\beta$. Linear gradient elution from 0 to 3M NaCl in sornipreparative HPLC showed TGF-$\beta$ at 1.5M NaCl. Gel filtration was less expensive and useful method for the purification of TGF-$\beta$.