• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1554-1559
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• 2013

A protease produced by Bacillus polyfermenticus SCD was purified and characterized as a new detergent material. The protease was purified from supernatant produced by B. polyfermenticus SCD, by ammonium sulfate precipitation, ion-exchange chromatography on a DEAE-Sephadex A-50, and finally gel filtration chromatography on Sephadex G-50. The molecular mass of this enzyme was 44 kDa based on SDS-PAGE. The optimum temperature and pH were $50^{\circ}C$ and pH 8.0. The ranges of its stability to the pH and temperature were 7.0 to 9.0 and under $40^{\circ}C$, respectively. The enzyme was highly stable in the presence of the surfactants like Triton X-100 (0.1%), showing a 2-fold increase in its proteolytic activity. However, the enzyme was slightly inhibited by the chelating agent EDTA (1 mM). The enzyme has a maximum activity at $50^{\circ}C$ and the activity can be increased by surfactants such as Triton X-100 and Tween 80.

• 한국축산식품학회지
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• 제39권1호
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• pp.73-83
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• 2019

The aim of this study was to investigate the effect of glucose oxidase (GOX) immobilized on magnetic chitosan nanoparticles (MCNP) on the viability of probiotic bacteria and the physico-chemical properties of drinking yogurt. Different concentrations (0, 250, and 500 mg/kg) of free and immobilized GOX were used in probiotic drinking yogurt samples. The samples were stored at $4^{\circ}C$ for 21 d. During storage, reduction of the number of probiotic bacteria in the samples with enzyme was lower than the control sample (without enzyme). The sample containing 500 mg/kg immobilized enzyme had the highest number of Bifidobacterium lactis and Lactobacillus acidophilus. The samples containing immobilized enzyme had lower acidity than other samples. Moreover, moderate proteolytic activity and enough contents of flavor compounds were observed in these samples. It can be concluded that use of immobilized GOX is economically more feasible because of improving the viability of probiotic bacteria and the physico-chemical characteristics of drinking yogurt.

• Bulletin of the Korean Chemical Society
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• 제18권10호
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• pp.1100-1104
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• 1997

Compounds containing a nitrone moiety were designed, synthesized and evaluated as a new type of active site zinc ligating substrate analog inhibitors for carboxypeptidase A. The kinetic results indicated that they are competitive inhibitors for the enzyme, supporting the design rationale that the oxygen of the nitrone forms a coordinative bond to the active site zinc ion. The present study demonstrates that nitrone is useful as a zinc coordinating ligand in the design of inhibitors for zinc containing proteolytic enzymes.

• Food Science and Biotechnology
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• 제17권4호
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• pp.766-771
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• 2008

The proteolytic enzyme from Saccharomyces sp. B101 was purified to homogeneity by ammonium sulfate fractionation, ultrafiltration, diethyl aminoethyl (DEAE)-Sephadex A-50 ion-exchange chromatography, and Sephadex G-100 gel filtration chromatography from the culture supernatant of Saccharomyces sp. B101. The specific activity and the purification fold of the purified enzyme were 4,688.9 unit/mg and 18, respectively. The molecular weight of the purified enzyme was estimated to be 33 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for the enzyme activity were pH 8.5 and $30^{\circ}C$, respectively. The enzyme activity was relatively stable in the pH range of 6.5-8.5 at below $35^{\circ}C$. The salt-tolerance and stability for the enzyme activity were relatively stable even at NaCl concentrations of 10 and 15%. The activity of enzyme was inhibited by $Ag^{2+}$ and $Fe^{2+}$, and activated by $Mn^{2+}$. In addition, the enzyme activity was potently inhibited by ethylenediaminetetraacetic acid (EDTA) and phenylmethyl sulfonylfluoride (PMSF). Based on these findings we concluded that the purified enzyme was a serine protease. Km and Vmax values for hammastein milk casein were 1.02 mg/mL and 278.38 unit/mL, respectively.

• Journal of Nutrition and Health
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• 제19권6호
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• pp.363-373
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• 1986

This study was devised to elucidate whether soused shrimp exhibits a digestive action on boiled pork meats. and the mechanism by which sousing with a high concentration of sodium chloride preserves nutrients in foods for a prolonged pe\ulcornerriod. Protease was isolated from soused shrimp using a combination of ammonium sulfate fractionation. DEAE - cellulose ion exchange chromatography and gel filtra\ulcornertion. The isolated protease had specific activity of 1.560 units. 210 purification fo\ulcornerld with an yield of 38%. Its optimum pH and temperature were 8.0 and $43^{\circ}C$ respectively. The molecular weight of the enzyme was 35.000. The Km value of the enzyme for casein was 1.6 x $10^{-6}$ M The e=yme required the presence of cu\ulcornerpric ion to exhibit its full activity. Eighty eight percent of the enzyme activity was in\ulcornerhibited by 3.5M NaCI showing a reversibly linear decrease of the enzyme activity as NaCI concentration increased. The nature of the inhibition by NaCl was rever\ulcornersible and noncompetitive. The protease activity in soused shrimp was well preser\ulcornerved with the elapse of time at least in part due to NaCI induced suppression of autodigestion. The enzyme was denatured by acid easily. i.e. 1% of the original activity remained after staying at pH 2 for 10 minutes. which is within the norm\ulcorneral range of pH of the human stomach. Soused shrimp was observed to be one of those containing the highest protease activity compared with the other soused foo\ulcornerds such as soused oyster. squid. clam. and Pollack intestine with respect to spec\ulcornerific activities of dialized 1:4 whole homogenates(w/v) in 5 mM sodium phospha\ulcornerte - 2.4 mM j3 - mercaptoethanol buffer. pH 8.0. Casein and boiled meats including pork, beef, and chicken appeared to be the good substrates for the protease. Casein was the best. Therefore. the ingestion of boiled meats including pork together with soused sh\ulcornerrimp would help digestion of boiled pork in human not only by increasing appe\ulcornertite also by the direct proteolytic digestion of boiled meats by soused shrimp to\ulcorner some extent. And a high concentration of sodium chloride inhibited the protease activity reversibly in a remarkable degree, which ensued in a significant retardat\ulcornerion of autodigestion of protein in foods by proteases, and hereby contributed to the preservation of foods for an extended period.

• 한국미생물·생명공학회지
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• 제2권1호
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• pp.13-17
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• 1974

토양에서 분리한 Streptomyces 속 중에 금속을 함유하고 있는 protease를 강하게 분필하는 균일 주를 선별하여 그 효소학적 성질 멸가지를 알아본 결과는 다음과 같다. 1 본 효소의 작용 최적 pH는 중성부근이며 최적온도는 37$^{\circ}C$ 부근이다. 2. 본 효소는 중성부근에서 비교적 안정하며 열에는 비교적 불안정하며 37$^{\circ}C$에서 100분간 열처리했을때 약 50% 가량 실활하였다. 3. Hg$^{＋＋}$, Cu$^{＋＋}$, Cd$^{＋＋}$, Ag$^{＋}$ 등에 의하여 강하게 조해되며, Mn$^{＋＋}$, $Mg^{＋＋}$, $Ca^{＋＋}$, Pb$^{＋＋}$, $Ba^{＋＋}$ 등에는 별 영향을 받지 않는다. 4. oxalate, citrate, 2-4-dinitrophenol, $\varepsilon$-amino caproic acid, thiourea, cysteine에 의해서는 강하게 조해되었다.

• 대한치과의사협회지
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• 제11권8호
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• pp.525-530
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• 1973

True collagenolytic enzymes in animal tissues were first demonstrated by Gross and Lapiere (1962), who showed the ability of such an enzyme in the culture medium of living explants of tadpole tissue to degrade a specific substrate of undenatured collagen under physiological conditions. Recently, tumor-associated collagenolytic activity has been demonstrated in human neoplasm and in ascites V Carcinoma. This investigation have been peforme to determine whether or not a collagen lytic enzyme could e found in isolated solid Tawa sarcoma of Donryu female rat obtained the culture medium. The results were as follows. 1. 11.5mg% of hydroxyproline contained in Donryu rat skin collagen, which was extracted by 0.5M acetic acid. 2. Cultivation of solid Tawa sarcoma tissues on reconstituted rat skin collagen gels showed lysis of adjacent gel after 18 hours, and much more extensive lysis after 5 days. 3. Collagen substrate was not attacked by the common proteolytic enzymes, trypsin, pepsin, and pronase.

• Current Research on Agriculture and Life Sciences
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• 제31권2호
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• pp.108-112
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• 2013

Nuts are one of the most common sources of allergies in individuals of all ages. In order for a particular protein to render an allergic reaction, it must resist proteolytic digestion by intestinal enzymes. In this study, three well-known allergenic nuts, almonds, cashew nuts, and peanuts, were used as samples, and enzyme digestion with Bacillus protease and porcine pepsin was tested. A proteomic approach using two-dimensional gel electrophoresis and an MS/MS analysis was applied to visualize and identify the proteins that were resistant to enzyme digestion. Among the 150 protein spots tested, 42 proteins were assigned functions. Due to the lack of genomic databases, 41% of the identified proteins were grouped as hypothetical. However, 12% of them were well-known allergens, including AraH. The remainder were grouped as storage, enzymes, and binding proteins.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.139-144
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• 1999

Lipoprotein lipase (LPL) I san enzyme that catalyzed the hydrolysis of triacylglycerols of chylomicrons and VLDL to produce 20acylglycerols and fatty acids. The enzyme, LPL, is localized on the surface of the capillary endothelium and is widely distributed in extrahepatic tissues including heart, skeletal muscle and adipose tissue. LPL has been isolated from boving milk by affinity chromatography on heparin-separose in 2 M NaCL, 5mM barbital buffer, pH 7.4. To elucidate the lipid-binding regin, LPL was digested with trypsin and then separated by gel filtration. Lipid binding region of LPL has been investigated by recombining LPL peptides with DMPC vesicles. Proteolytic LPL fragments with DMPC were reassembled and stabilized by cholate. Lipid-binding region of LPL was identified by a PTH-automated protein sequencer, as AQQHYPVSAGYTK. The analysis of the secondary structure of the lipid-binding peptides revealed a higher probability of $\alpha$-helix structure compared to the whole LPL protein. The prediction of hydrophobicity of lipid -binding region was highly hydrophobic (-1.1) compared to LPL polypetide(-0.4).

• 한국식품과학회지
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• 제23권4호
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• pp.452-458
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• 1991

체다치즈 숙성기간 중 존재하는 저온성세균을 분리하여 단백질분해능이 우수한 균주를 선발하였고 이 선발된 균주가 생산하는 효소의 특성을 연구하였다. 체다치즈 숙성기간 중 미생물의 변화를 관찰한 결과 내냉성세균이 일정하게 유지되고 있었는데 그 중 200개의 균주를 1차 선발한 후 단백질분해능이 우수한 균주 3개를 분리, 동정한 결과 P. fluorescens 두 종과 A. denitrificans였다. 그 중 활력이 가장 높은 P. fluorescens 65가 생산하는 효소를 gel filtration에 의해 정제한 결과 $190{\sim}230ml$ elution volume에서 protease가 용출되었고 SDS-PAGE로 분석한 결과 분자량은 47,000인 것으로 나타났으며 아미노산 조성은 Glu(14.96%)와 Ser(13.83%)의 함량이 제일 높았고 Met, Trp은 존재하지 않았다. P. fluorescens 65의 성장곡선에 따른 효소활력을 실험한 결과 세포증식이 활발한 대수증식기에서 단백질분해효소를 많이 분비함이 나타났으며 pH는 변화가 없이 일정하였다. Extracellular protease 65의 반응 최적온도는 $45{\sim}50^{\circ}C$ 사이었으며 최적 pH는 6.0으로 나타났다.