• Korean Journal of Microbiology
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• v.39 no.4
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• pp.230-234
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• 2003

An extracellular protease of Bacillus amyloliquefaciens S94 was purified to apparent homogeneity. The enzyme activity was strongly inhibited by general inhibitor for serine protease, PMSF, suggesting that the enzyme is a serine protease. The purified enzyme activity was inhibited by leucine peptidase inhibitor, bestatin, suggesting that the enzyme is a leucine endopeptidase. When the enzyme was chemically modified with PMSF, which specifically reacted with serine residue on the enzyme, the activity was eliminated. The endopeptidase activity was inhibited by the modifier which chemically modified carboxyl group of aspartate and glutamate. PLP, which would modify lysine residue, did not affect the endopepetidase activity to a greater extent. This demonstrates that serine and aspartate (or glutamate) residues of enzyme would participate in a important function of the endopeptidase activity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.94-94
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• 1993

Angiotensin 전환효소 억제제를 재료로하여 다기관 협동을 통한 시판 후 조사방법론을 개발하고, 아울러 Angiotensin 전환효소 억제제 투여시 나타나는 기침의 발생율과 이와 관련된 요인을 밝히고자 시판 후 조사를 시도하였다. 방법: 1992년 2월부터 1992년 10월까지 11개 병원 가정의학과를 방문하여 Angiotensin 전환효소 억제제를 투여한 고혈압 환자 348명을 연구대상으로 하였다. 이중 남자가 147명, 여자가 201명이었으며, 연령별로는 39세이하 38명, 40-54세 156명, 55세 이상이 154명이었다. 최초 약물투여 후 2, 4, 8, 12주에 추적 관찰하였으며, 기침의 발생율은 PC-SAS 6.04를 이용하여 Kaplan-Meier 방법과 Log-Rank 방법으로 분석하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.42-42
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• 1993

Angiotensin converting enzyme (ACE)은 혈압 상승작용과 밀접한 관계가 있는 효소이다. 따라서 이 효소의 작용 억제는 혈압 강하를 초래한다. 본 실험에서는 ACE와 여러점에서 유사점을 가진 Carboxypeptidase A에 대하여 강력한 억제 효과를 나타내는 간단한 구조의 억제제를 개발한 바 있는데. 이때 사용한 억제제 설계방법을 ACE 억제제 개발에 적용시켜 ACE 억제를 통한 고혈압 강하제 개발을 목적으로 하였다. ACE 억제작용에 있어서의 알려진 구조-활성 상관 관계와 ACE의 활성부위를 기초로 해서 아래와 같은 구조의 물질을 억제작용 보유의 물질로 설계하고 합성하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.229-234
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• 2011

This study investigated quality characteristics of 4 year-old ginseng by enzymatic hydrolysis conditions to increase utilization. Ginseng was ground after steaming and was each treated with hydrolase A, B, C and D. When quality characteristics by the enzymes were examined, no significant difference was observed with pH of 5.5~5.6 and the sugar content of 4.0~4.33. The crude saponin content was the highest in ginseng treated with D, followed by B, C and A. The crude saponin, the reducing sugar and the total sugar contents increased until 0.3% (w/w) concentration in enzyme D with no significant difference by its concentration. Although active ingredients increased with time passage of hydrolysis, no significant change was found after three hours and the crude saponin content was the highest when ginseng was treated at $60^{\circ}C$. From these results, optimum conditions for 4 year-old ginseng were $60^{\circ}C$ for 3 hours with 0.3% (w/w) enzyme D, and under these conditions the reducing sugar, the total sugar and the crude saponin contents recorded 18.11, 36.21 and 4.23 mg/g, respectively. Therefore, enzymatic hydrolysis was found to be effective in increasing active ingredients of 4 year-old ginseng with various usages expected.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.270-270
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• 1994

돼지 뇌조직으로부터 순수 분리 정제된 Glutamate decarboxylase (GAD)는 효소 dimer당 0.8mole 보조 인자인 pyridoxal-5-phosphate(PLP)가 강하게 binding되어 있었다. 이러한 부분적으로 resolved된 효소에 외부로부터 PLP를 넣어주면 효소의 활성도는 최대값으로 증가하였다. 정제된 GAD는 sulfydryl시약에 의한 화학변형에 의하여 효소의 활성도를 상실하였으며 환원제인 dithiothreitol이나 2-mercaptoethanol의 첨가에 의하여 효소의 활성도가 복구되는 것으로 보아 효소의 활성부위의 활성에 직접 관여하는 중요한 cysteinyl잔기가 존재하고 있는 것을 알 수 있다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.205.1-205
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• 1978

일반적으로 쌀막걸리 중에는 풍미에 관여한다고 생각되는 핵산관련물질이 핵산분해효소인 PDase (phosphodiesterase) 및 PMase (phospomonoesterase) 등의 작용을 받아 대부분이 분해되는 것으로 알려져 있다. 따라서 저자등은 쌀막걸리 제조공정을 통하여 핵산관련물질의 분포와 그와 관련된 핵산 분해효소에 대한 실험을 하였다. 본보에서는 제국중 핵산관련물질과 핵산관련물질을 분해하는 효소의 경시적 변화를 조사하였으며 이들 분해효소의 효소학적 성질을 검토하여 몇가지 결과를 얻었으므로 보고하는 바이다.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.28 no.3
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• pp.97-107
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• 2017

The present study was conducted to investigate the effects on growth performance, nutrient digestibility, and gut health of broiler chickens when a dietary supplementation of multienzymes was added to diets, containing different energy levels. A total of 480 broiler chickens of similar body weight (Ross 308, 1-day-old) were randomly subjected to four treatments. The dietary treatments included a corn-soybean meal-based diet supplemented with: multienzyme (amylase+protease+ mannanase+xylanase+phytase), 0.05% enzyme, and different energy levels (3010 and 3060 kcal/kg). The experimental diets were fed to the chicks in a mash form for 35 days in two phases (1-21 d, phase I; and 22-35 d, phase II). During the overall period, chicks fed with diets supplemented with multienzymes had a better weight gain (p<0.05) and feed conversion ratio (FCR) than those fed with diets without enzymes. There was no difference in the growth rate and FCR among the chicks fed with diets supplemented with enzymes, even though the dietary energy levels were different. The apparent fecal and ileal digestibility of dry matter, gross, crude protein, calcium, and phosphorus were significantly enhanced (p<0.05). The population of cecal and ileal Lactobacillus spp. was significantly increased (p<0.05), and Clostridium spp. and coliforms were significantly decreased (p<0.05) in diets supplemented with enzymes. Villus height and villus height to crypt depth ratio in the small intestine was also significantly enhanced (p<0.05) in diets supplemented with enzymes. In conclusion, multienzyme supplementation had positive effects on the weight gain of broilers, FCR, digestibility of nutrients, and on the growth of intestinal microbiota.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.121-128
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• 2006

The purified xylanase from Bacillus alcalophilus AX2000 was modified with various chemical modifiers to determine amino acid residues in the active site of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results suggested that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and N-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.761-766
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• 2008

The effects of various enzymes and emulsifiers on the loaf volume and crumb hardness of rice breads were studied. Four different enzymes [fungal ${\alpha}$-amylase (AMYL), maltogenic bacterial ${\alpha}$-amylase (NMYL), glucose oxidases (GO), and xylanase+hemicellulases (PTP)] and four emulsifiers [sorbitan monostearate (SMS), glycerol monostearate (GMS), sodium stearoyl lactylate (SSL), and glycerol ester+propylene glycol ester+sucrose ester+sorbitan ester (SP)] were supplemented to rice dough. The addition of AMYL, GO, and GO+AMYL increased loaf volume of rice breads. The highest loaf volume was observed in rice bread supplemented with AMYL. Rice breads supplemented with enzymes firmed at lower rates during storage, and AMYL, NMYL, and GO considerably decreased crumb hardness of rice breads, exhibiting a significant antistaling effect. The addition of emulsifiers produced rice breads with better specific loaf volume and crumb texture, and continuously retarded crumb hardness of rice breads during storage. Especially, rice bread supplemented with SSL demonstrated the highest loaf volume and the lowest crumb hardness during storage.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.409-415
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• 2007

This experiment was conducted to investigate the effects of dietary enzyme mixture fortified with ${\beta}-glucanase$ on the growth performance, serum components and meat quality of broiler chicks. 31,800 Ross 208 male broiler chicks were randomly allotted into 2 groups, the control and 0.3% enzyme diet with ${\beta}-glucanase$ supplementation groups. Control group chicks were fed the control (corn-soybean meal based) diet and the treatment group chicks were fed the 0.3% enzyme mixture supplemented with ${\beta}-glucanase$. The growth performance, serum components and meat qualities such as pH, color, water holding capacity, cooking loss, and shearing force of meats were investigated. The results showed that the growth performance of chicks fed the 0.3% enzyme mixture diet were improved compared to that of the control group, as much as 5% in growth rate, 19% in average weight, 6.8% in performance index, and 5.5% in feed efficiency. Although, there were no significant differences in the muscle color degrees ($L^*a^*b^*$) and shearing force between the control group and experimental group, the water holding capacity and cooking loss of the experimental group were significantly higher than those of control group (p<0.05). The antibody titers in serum against the antigens of Newcastle disease and Infectious Bursal disease were higher in the experimental group than in the control group. Altogether, these suggest that the broiler diet containing 0.3% enzyme mixture fortified with ${\beta}-glucanase$ activity can improve the growth performance, immune reaction, and meat quality of broiler chicks.