• Journal of Life Science
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• v.25 no.3
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• pp.317-322
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• 2015

Alcohol-induced fatty liver (steatosis) results from excessive generation of reducing equivalents by ethanol metabolism. Generally, chronic ethanol treatment causes hepatosteatosis by regulating sterol regulatory element-binding protein 1c (SREBP-1c), which increases the synthesis of hepatic lipids. The effect of ethanol on SREBP-1c is mediated through mammalian sirtuin-1 (SIRT-1), a NAD⁺-dependent protein deacetylase that regulates hepatic lipid metabolism. Ginseng is a widely used herbal medicine that is used in Asia for its anti-diabetes and anti-obesity effects. The pharmacological and therapeutic effects of ginseng are primarily produced by bioactive constituents known as ginsenosides. Here, we examined the regulatory effects of Korean red ginseng (KRG) extracts on SREBP-1c and SIRT-1 on lipid homeostasis in AML-12 mouse hepatocytes. AML-12 cells were treated with ethanol and/or KRG extracts (0 - 1,000 μg/ml). Lipid droplets were assayed using Oil red O staining, and western blotting was used to measure SIRT-1 and SREBP-1 expression. Treatment with KRG extracts restored SIRT-1 expression and reduced SREBP-1c expression in ethanol-treated cells. We also showed that KRG extract and ginsenosides Rb₂ and Rd significantly decreased SREBP-1 acetylation in ethanol-treated cells. These results show that treatment with KRG extract and its active ginsenoside constituents Rb₂ and Rd protected against alcohol-related hepatosteatosis via regulation of SIRT-1 and downstream acetylation of SREBP-1c, which altered hepatic lipid metabolism.

• KSBB Journal
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• v.15 no.3
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• pp.238-242
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• 2000

A fusion protein of human interleukin-2(hiL-2) and glucagon which was expressed in Escherichia coli. was digested with enterokinase for recovery of hIL-2 from the fused protein. To obtain hIL-2 of optimum recovery hydrolysis reaction were performed under various conditions of urea additives and reaction time. hIL-2 was finally purified by RP-HPLC(reversed phase-HPLC) to remove cleaved G3 fusion partner and residual uncleaved G3-IL-2 HIL-2 was eluted in a single peak at 100% acetonitrile at 28 min. Optimum urea concentration was found to be 0.5 M and 24 h reaction time was sufficient without any additive such as CaCl2 and Tween-20.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.294-299
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• 1992

This study was to examine the effect of functional properties of soy protein isolate(SPI) and qualities of soybean curd upon proteolytic hydrolysis. SPI was hydrolyzed using proteolytic enzyme, bromelain. The protein content of SPI by microkjeldahl method was 84% and the degree of hydrolysis in modified soy protein isolate(MSPI) was 2.7%. The solubility of MSPI was higher than that of control at various pH tested and proteolytic hydrolysis was increased emulsion formation and foam expansion while decreased emulsion stability, foam stability and calcium precipitation. Modified soybean curdI, standard soybean milk: Modified soybean milk=3:1, was soft and springy soybean curd when the texture properties of soybean curd were tested by texture profile analysis using Instron and sensory evaluation. The rheological model of soybean curds was investigated by stress relaxation test. The analysis of relaxation curve revealed that the rheological behavior of soybean curds could be expressed by 7-element generalized Maxwell model. The equilibrium modulus and modulus of elasticity decreased as the ratio of modified soybean milk was increased.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.305-310
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• 1987

The enzymatic properties of ${\beta}-amylase$ from soybean and sweet potato were compared. The sweet potato enzyme consists of four identical subsunits whereas soybean enzyme has no subunit $structure^{12,\;15)}$. In the denatured state, both enzymes exhibited the same molecular weight on SDS-gel electrophoresis and on gel-filtration analysis. The spectra of circular dichroism revealed that both enzyme have almost same secondary structure but the environment of aromatic side chains are different. The chemical cleavage of soybean and sweet potato ${\beta}-amylases$ at cysteine residues and methionine residues demonstrated the homology of amino acid sequence between the enzymes. The similarity between soybean and sweet potato ${\beta}-amylase$ was also revealed by immunological method. The antibody for soybean enzyme inhibited the activity of sweet potato enzyme but it did not inhibit the activity of wheat, barley and Japanese-raddish ${\beta}-amylases$.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.71-77
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• 1992

A 50 KD metalloprotease of Serratia marcesrens ATCC 21074 was purified by ammoniumsulfate precipitation. DEAE-cellulose ion exchange chromatography, and sephadex ti-100gel filtration. Optimal pH and temperature of enzyme were pH 8.0 and 37"C, respectively.This enzyme was stable in the ranges of 10-37$^{\circ}$C and pH 5.0--11.0. Thermal denaturationwas investigated by differential scanning calorimetry. Onset temperature of denaturationand endothermic peak temperature were 376$^{\circ}$C and 43.2"C. re:,pectively. The denaturationenthalpy was -8.4mJimg. The purified metalloprotease was ri.sistant to autodigestion for24 hr at 30$^{\circ}$C. Metalloprotease in culture supernatant was also resistant to autodigestionin this conditions. Heat-denatured enzyme. however. was rapidly digested by the nativeenzyme. The metalloprotease was stable to proteolytic digestion by mammalian proteasessuch as trypsin. a-chymotrypsin, and elastase. But the enzyme was easily digested bybacterial protease. thermolysin.bacterial protease. thermolysin.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.515-522
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• 1998

Plant root rotting fungi, Fusarium solani are suppressed their growth by the chitinase which is produced from the antagonistic soil bacteria. The chitinase producable antagonistic bacterium Pseudomonas sp. 3098 was selected as a powerful biocontrol agent of F. solani from ginseng rhizosphere. The antagonistic Pseudomonas sp. 3098 was able to produce a large amount of extracellular chitinase which is key enzyme in the decomposition of fusarial hypal walls. The chitinase was purified from cultural filtrate of Pseudomonas sp. 3098 by the procedure of ammonium sulfate precipitation, anion exchange chromatography, gel filtration on Bio-Gel P-100, and 1st and 2nd hydroxyapatite chromatography. The molecular mass of the purified enzyme was ca. 45 kDa on SDS-FAGE. The optimal pH and temperature for the activity of purified chitinase were 5.0 and 45$^{\circ}C$, respectively. The enzyme was stable in pH range of 5.0 to 9.0 up to 5$0^{\circ}C$ The enzyme was significantly inhibited by metal compounds such as FeCl$_2$, AgNO$_3$ and HgCl$_2$, and was slightly inhibited by p-CMB, iodoacetic acid, urea, 2,4-DNP and EDTA. The enzyme had ability of digestion on colloidal chitin and chitin from shrimp shell, but could not digest chitosan and chitin from crab shell. Km value of the enzyme was 0.11% on colloidal chitin, and the maximum hydrolysis rate of the enzyme was 34% on colloidal chitin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.383-391
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• 1992

A comparative study of enzymatic properties between the trypsin from the cat-shark Cephaloscyllium umbratile ( C-T) and the two trypsins from the mackerel Scomber japonicus $(M-T_A\;and\;M-T_B)$ was carried out following after the previous paper(Pyeun et al., 1991). Trypsin from cat-shark(C-T) showed the higher heat stability compared to the others $(M-T_A\;and\;M-T_B)$ and its denaturation constant$(K_D)$ was $10.68\times10^{-4}\;sec^{-1}\;at\;55^{\circ}C$ with BA-p-NA substrate. The activation energies(Ea) of the trypsins measured at a temperature range from $30^{\circ}C\;to\;50^{\circ}C$ were estimated to be 4.07 kcal/mole for C-T, 11.61 kcal/mole for $M-T_A$, and 8.43kcal/mole for $M-T_B$, respectively. The Km values were $24.9\times10^{-5}\;M\;for\;C-T,\;5.37\times10^{-5}\;M\;for\;M-T_A,\;and\;9.65\times10^{-5}\;M\;for\;M-T_B$. On the other hand, the Ki values for TLCK and DFP determined by Dixon plot were $1.50\times10^{-6}\;M\;and\;9.28\times10^{-6}\;M\;for\;C-T\;2.86\times10^{-6}\;M\;and\;2.11\times10^{-4}\;M\;for\;M-T_A\;and\;3.90\times10^{-6}\;M\;and\;1.60\times10^{-4}\;M\;for\;M-T_B$ Similar amino acid profiles were showed between three trypsins each other, with few exceptions of $M-T_B$ containing higher amount of arginine, and the smaller amount of tryptophan in C-T than the others.

• Journal of Life Science
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• v.9 no.6
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• pp.733-736
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• 1999

The doubly altered mutant tryptophan synthase $\alpha$-subunits, in which Thr 24 was replaced by Ser, Leu or Lys in addition to F139W substitution, were purified. Urea-induced unfolding equilibrium curves of these proteins, monitored by fluorescence intensity of tryptophan, show that the alterations of residue 24 resulted in marked changes in folding properites, suggesting the importance of this residue in folding of this protein.

• Korean Journal of Human Ecology
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• v.2 no.2
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• pp.29-38
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• 1999

저항전분(RS)은 건강한 사람의 소장에서 소화되지 않는 전분이나 전분질 식품의 부분이다. 저항전분은 4가지 형태로 구분하는데 RS 1은 물리적으로 효소와 만나지 않는 부분, RS 2는 생전분으로 감자, 바나나와 고아밀로오스 옥수수전분, RS 3는 노화된 전분 그리고 RS 4는 화학적으로 변성시킨 전분이다. RS 함량은 열에 안정한 $\alpha$ -아밀라아제나 pancreatin, pancreatic $\alpha$ -아밀라아제와 미생물에서 분리된 아밀라아제 등을 이용한 몇 가지 방법에 의해 분석되고 있다. RS는 대장에서 미생물에 의해 발효되어 단쇄지방산을 생성하는데 특히 부티릭산이 생성된다. 아세트산이나 프로피온산은 간의 대사에 영향을 주며 부티릭산은 항 종양(항 대장암) 특성이 있다. RS는 소화가 되지 않아 저열량원이므로 당뇨병 환자나 운동에 의한 혈당 조절이 필요할 때 조절능력을 갖는다. RS가 건강에 중요한 인자임이 알려지면, 건강을 위해 매일 섭취량의 증가를 권장해야 할 것이다.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.45-45
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• 2001

종이 표변에 전분 사이징을 하는 목적은 종이가 액체에 대하여 침투저항성을 부여하 여 종이의 인쇄적성을 향상시키며 아울랴 종이의 표면적성과 종이강도 등의 물리적 특 성을 향상시키기 위해서 사용된다. 표면 사이징은 기본적으로 종이 표면에 전분을 이용 한 필름을 형성하여 종이 표면의 공극크기를 줄여 인쇄잉크 등과 같은 액체의 침투속 도를 늦여준다. 현재 국내에서 널리 사용되는 표면 사이징용 전분으로는 산화전분과 자 가변성용 일반전분이 있다. 자가변성용 전분은 효소나 APS로 전분의 chain 길이를 적 당한 점도로 잘라주는 것으로 전분 호액의 노화가 쉽게 일어나는 경향이 있다. 산화전 분은 전분회사에서 산화제를 이용하여 전분의 점도를 사용자의 요구에 따라 조절한 것 으로 water holdout이 개선되고 자가변성용 전분보다는 노화 안정성이 개선되지만 종 이 내부로의 칩투가 많이 일어나 전분 필름 강도가 약해지며 표면 강도 향상 효과가 적고 종이의 광학적 특성을 저하시키는 단점을 지니고 있다. 또한 약 10 ~ 20% 정도 사 용되는 파지의 재활용시 펄프 섬유에 흡착되지 않는 전분으로 인해 백수 내의 COD 및 B BOD를 증가시키는 원인이 된다.따라서 본 연구에서는 펄프 섬유와 친화력이 높아 지료 내첨용 지력증강제로 널리 사용되고 있는 양성 전분의 양이온 치환도 및 점도를 사이즈 프레스에 적합하게 조절 하여 백상지 제조업체의 라언에 적용하였다. 결과분석 항목으로는 파지 재활용에 따른 백수내 COD, 칼숨 이온함량 등의 백수 시스템의 변화와 종이의 물리적, 광학적 특성 및 ink jet 용지의 인쇄적성 등을 측정하여 산화전분과 비교하였다. 그 결과 약 20%의 C COD 감소 효과와 10%정도의 OPR 향상 효과를 얻을 수 있었다. 종이 물성의 경우 인 장강도와 뺏뺏이(stiffness) 및 지분 등을 측정한 결과 산화전분 보다 향상되었다. 특히 지분의 경우, 참여한 회사의 지분관련 complain이 약 80% 정도 감소하는 결과를 나타 내었다. 또한 백상지의 경우 ink jet 프린터에 많이 사용됨으로 ink jet 프린터의 인쇄 적성을 image analyzer로 측정한 결과 산화전분 보다 향상된 결과를 나타내었다.