• Preventive Nutrition and Food Science
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• 제10권3호
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• pp.239-243
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• 2005

Angiotensin I-converting enzyme (ACE) inhibitory activities of elk antler hydrolysates prepared with three kinds of proteases, pepsin, trypsin and $\alpha-chymotrypsin$, were investigated. The ACE inhibitory activity of the pepsinolytic hydrolysate was the highest with an $IC_{50}$ value of $9.3\mu g/mL.$ In addition, three kinds of pepsinolytic hydrolysates with relatively high molecular weights (over 10,000 Da), medium molecular weights (5,000 to 10,000 Da), and low molecular weights (below 5,000 Da) were fractionated using an ultrafiltration membrane system. The below 5,000 Da hydrolysate exhibited the highest ACE inhibitory activity. These results indicate that the pepsinolytic hydrolysates of elk velvet antler could be a good source of peptides with ACE inhibitory activity.

• Fisheries and Aquatic Sciences
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• 제13권3호
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• pp.216-223
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• 2010

Abalone (Haliotis discus hannai), mostly distributed and maricultured in southwestern coastal areas of South Korea, is recognized as an economically important species in the fishery industry. Abalone intestines are one of the by-products of abalone processing. To investigate abalone intestines as bioactive substances, abalone intestine gastrointestinal digests (AIGIDs) of various molecular weights (MWs) were prepared using in vitro gastrointestinal digestion and an ultrafiltration system, and tested for inhibitory effects against reactive oxygen species (ROS) and oxidative stress in macrophage cells treated with hydrogen peroxide ($H_2O_2$). In our results, among AIGIDs, AIGID-III (MW=5-10 kDa) showed potent inhibitory activities for lipid peroxidation and free radicals. Additionally, the results clearly indicated that AIGID-III treatment could prevent cytotoxic damage of macrophages by $H_2O_2$-induced oxidative stress due to its potent scavenging ability against cellular ROS. These results suggest that AIGIDs may have protective and therapeutic potential for oxidative stress syndromes and immune diseases through ROS inhibition in macrophage cells.

• 생약학회지
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• 제26권2호
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• pp.148-153
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• 1995

As an initial step for evaluating hepatoprotective components against alcohol-induced toxicity, the effect of various fractions from Aloe vera on alcohol metabolism in rats were examined and the results were as follows: Water soluble fraction, after a single oral administration to rats, was found to cause a significant decrease in the serum ethanol concentration as well as enhancement of liver cytosolic ADH activity. On the other hand, the fractions soluble in organic solvent was found to cause an increase in the blood ethanol concentration and inhibit ADH activity. Further fractionation of the water soluble fraction by ultrafiltration system gave four subfractions corresponding to molecular weight and treatment of them in rats demonstrated that subfraction of M.W. > 30,000 exhibited the most potent enhancing activity of ethanol methabolism.

• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 춘계 총회 및 학술발표회
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• pp.26-27
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• 1995

Most of synthetic polymeric membranes used in ultrafiltration, reverse osmosis and microfiltration processes are prepared by phase inversion(or phase separation) technique. In this technique, a homogeneous polymer solution is cast into thin film or hollow fiber shape and then immersed into a nonsolvent coagulant bath. The exchange of solvent and nonsolvent across the interface between casting solution and coagu!ant can make the casting solution phase-separate and form a membrane with a symmetric or asymmetric structure. Because of importance of this technique in membrane field, many investigations have been dedicated to elucidate the mechanism of membrane formation by phase inversion technique.[1-10] These investigation have suggested that the structure formation and permeation properties of phase inversion membrane depend on the variables such as the nature and content of casting solution and coagulant, temperature of casting solution and coagulant, and the diffusional exchange rate of solvent and nonsolvent etc. which can be related to the thermodynamic and kinetic properties of the casting system. The variables such as the nature and content of casting solution can also be the important factor affecting the structure formation and permeation property of the phase inversion membrane.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.134-139
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• 2005

Seven brown algal species (Ecklonia cava, Ishige okamurae, Sargassum fulvellum, Sargassum horneri, Sargassum coreanum, Sargassum thunbergii and Scytosiphon lomentaria) were hydrolyzed using five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase) and screened for angiotensin 1-converting enzyme (ACE) inhibitory activities. Most algal species examined showed good ACE inhibitory activities after the enzymatic hydrolysis. However, E. cava was the most potent ACE inhibitor of the seven species. Flavourzyme digest of E. cava exhibited an $IC_{50}$ of around $0.3\;{\mu}g/mL$ for ACE; captopril has an $IC_{50}$ of $\~0.05\;{\mu}g/mL$. The Flavourzyme digest was separated to three fractions by an ultrafiltration membrane (5, 10, 30 kDa MWCO) system according to the molecular weights. The active components were mainly concentrated in >30 kD fraction which are composed of the highest protein content $(27\%)$ and phenolic content (261 mg/100 mL) compared to the other two smaller molecular weight fractions. Therefore, the active compounds appear to be relatively high molecular weight complex molecules associated with protein (glycoprotein) and polyphenols. Therefore, E. cave is a potential source of antihypertensive compound.

• 한국가축번식학회지
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• 제21권4호
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• pp.397-403
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• 1997

Retrovirus vector를 이용한 형질전환 동물의 생산에 있어서 시급히 선행되어야 할 가장 중요한 요소는 표적세포에 대해 높은 감염도를 가진 virus를 생산하는 system의 개발이다. 이러한 문제를 해결하기 위한 일환으로 본 연구에서는 세 가지 방법을 사용하여 세포 배양액 속의 virus의 농도를 높여줌으로써 retrovirus vector system에서 생산되는 virus의 낮은 감염도를 극복하고자 하였다. 이 실험에서 얻어진 결과는 다음과 같다. 1) Virus를 생산하는 세포(pG13-LN$\beta$Z retrovirus producing cell)를 5mM의 Na-butyrate로 처리했을 때 virus titer는 소의 embryonic trachea 표적세포에서 약 3배의 증가를 나타냈다. 2) Virus가 들어있는 세포 배양액을 ultrafiltration을 통해 농축한 결과, 농축액 속의 virus titer는 대조구에 비해 약 3.6배 증가하였다. 3) 초원심분리를 통해 농축된 virus stock의 titer는 소의 embryonic trachea 표적세포에서 약 1.0$\times$105LacZ+TU/ml였는데 이 방법은 대조구에 비해 약 12.5배 만큼의 titer의 향상을 가져왔다. 따라서, 이와같이 농축된 virus stock을 이용할 경우 retrovirus vector system을 이용한 소의 수정란에의 유전자 전이율을 현저히 향상시킬 수 있으리라 사료된다.

• Fisheries and Aquatic Sciences
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• 제15권2호
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• pp.137-143
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• 2012

The abalone Haliotis discus hannai, is one of the economically important species in the fisheries industry. Abalone intestines are one of the by-products of its processing. To investigate its bioactive potential, abalone intestine was digested using an in vitro gastrointestinal (GI) digestion system containing pepsin, trypsin, and ${\alpha}$-chymotrypsin. The abalone intestine G1 digests (AIGIDs) produced by the GI digestion system were fractionated into AIGID I (> 100 kDa), AIGID II (10-100 kDa), and AIGID III (1-10 kDa) using an ultrafiltration membrane system. Of the three digests, AIGID II and AIGID III exhibited inhibitory effects against matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) in HT1080 human fibrosarcoma cells. Both fractions potently inhibited gelatine digestion by MMP-2 and MMP-9 treated with phorbol 12-myristate 13-acetate (PMA) and migration of HT1080 cells in dose dependently. Furthermore, AIGID II and III attenuated expression of p65, a component of nuclear transcription factor kappa B. These results indicate that of the abalone intestine digests inhibit MMP-2 and MMP-9. Thus, the AIGIDs or their active components may have preventive and therapeutic potential for diseases associated with MMP-2 and MMP-9 activation in fibrosarcoma cells.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1007-1014
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• 2015

Plectasin, the first defensin extracted from a fungus (the saprophytic ascomycete Pseudoplectania nigrella), is attractive as a prospective antimicrobial agent. The purpose of this study was to establish a bacterium-based production system and evaluate the antimicrobial activity of the resulting plectasin. A gene encoding plectasin, with the codon preference of Escherichia coli, was optimized based on its amino acid sequence, synthesized using genesplicing with overlap extension PCR, and inserted into the expression vector pGEX-4T-1. The fusion protein was expressed in the soluble fraction of E. coli and purified using glutathione Stransferase affinity chromatography. Plectasin was cleaved from the fusion protein with thrombin and purified by ultrafiltration. The purified plectasin showed strong, concentrationdependent antimicrobial activity against gram-positive bacteria, including antibiotic-resistant bacteria, especially penicillin-resistant Enterococcus faecium. This antimicrobial activity was equal to chemically synthesized plectasin and was maintained over a wide range of pH and temperatures. This soluble recombinant expression system in E. coli is effective for producing plectasin at a relatively lower cost, and higher purity and efficiency than prior systems, and might provide a foundation for developing a large-scale production system. Overall, plectasin shows potential as a novel, high-performance, and safe antibiotic for the treatment of refractory diseases caused by drug-resistant bacterial strains.

• 대한환경공학회지
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• 제22권2호
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• pp.323-329
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• 2000

막결합형 활성슬러지 공정은 막오염으로 인한 플럭스 감소 때문에 시스템의 경제성과 효율성이 떨어지는 문제점을 지니고 있어 막오염에 대한 체계적인 연구가 요구되고 있다. 따라서 본 연구에서는 한외여과막과 결합된 활성슬러지 시스템을 운영하면서 막오염 유발 인자를 규명하고자 하였다. 활성슬러지 공정의 운전 초기에 급격한 플록 크기 감소와 동시에 급격한 플럭스 감소가 관찰되었다. 초기 플럭스 감소현상은 활성슬러지 플록의 입자 크기 감소로 인한 케이크 저항의 증가가 주요 원인이었다. 이것은 운전시간에 따른 각 여과 저항값을 측정하여 확인하였다. 또한, 플록 해체로 인하여 EPS 양이 운전 전보다 약 150 % 가량 증가한 것을 볼 때 EPS 양의 증가가 케이크 저항 증가의 또 다른 원인이 될 수 있음을 제시하였다.

• 멤브레인
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• 제17권3호
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• pp.161-173
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• 2007

현재 막여과 공정은 정수처리에서 많은 관심을 받고 있다. 그러나 막여과 공정은 저압 운전이 가능한 정밀/한외여과 분리막을 이용할 때는 효과적인 용존성 유기물 제거가 이루어지지 않으며 막오염 현상으로 분리막의 투과도 감소가 일어난다. 고압 분리막을 이용할 경우 양질의 수질은 얻을 수 있으나 고압 운전으로 인하여 운전비용의 소모가 높다. 따라서 최근 분리막의 효율적인 정수처리 적용과 성능 향상을 위해서 다른 물리화학적 공정과 결합한 혼성공정에 대한 다양한 접근이 이루어지고 있다. 본 연구에서는 혼성공정으로 응집, 흡착, 특정 화학반응, 막표면 코팅 등과 정밀/한외여과 공정을 결합한 경우의 특징, 처리효율, 고려사항 등을 고찰하였다.