• 한국수산과학회지
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• 제41권3호
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• pp.176-181
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• 2008

To evaluate the effective use of endoprotease from squid viscera as a food processing aid, various methods of fractionating endoprotease from viscera of the Argentina shortfin squid (Illex argentinus) were evaluated. The endoprotease-positive fractions of each fractionation were fraction II (30-40%, w/w) with cold acetone, fraction IV (50-60% saturation) with ammonium sulfate, fraction UF with anion exchange chromatography, and fraction II (15-24 kDa) with gel filtration. The specific activities (approximately 25 U/mg) of the fractions using ammonium sulfate and gel filtration were higher than the others. Total azocaseinolytic activity and recovery of the positive fraction using gel filtration were 806.95U and 37.82%, respectively, and were the highest among the positive fractions. Based on the results, gel filtration was the most efficient method for fractionating endoprotease from the viscera of Illex argentinus.

• Fisheries and Aquatic Sciences
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• 제15권4호
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• pp.283-291
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• 2012

This study examines the optimal fractionation method and conditions for the isolation of endoprotease- and exopeptidase-active fractions from crude extracts of cuttlefish hepatopancreas (HP) using four fractionation methods: ammonium sulfate fractionation (ASF), polyethylene glycol fractionation (PGF), ion exchange chromatography (IEC), and gel filtration chromatography (GFC). Total endoprotease activity highest in the fraction II (concentrate of fractions 34-42; 842.60 U) of GFC, followed by fraction III (40-60% ammonium sulfate fraction; 670.25 U) of ASF, fraction I (concentrate of fractions 8-12; 436.89 U) of IEC, and fraction II (10-20% polyethylene glycol; 307.31 U) of PGF. Total exopeptidase activity of these fractions was highest in fraction II (2,704.70 U) of GFC, fraction III (2,110.50 U) of ASF, fraction III (1,605.60 U) of PGF, and fraction II (concentrate of fractions 38-44; 1,196.22 U) of IEC. These results showed that fraction II of GFC had the highest activity toward both exopeptidase and endoprotease, with exopeptidase activity being 3.21 times higher than of endoprotease. These results suggest cuttlefish HP could be used as a potential source for the extraction of exopeptidase, an enzyme capable of catalyzing the cleavage of N- and C-terminal amino acids in polypeptides, Like endoprotease, the most efficient method for separating exopeptide-active fractions was GFC.

• Applied Biological Chemistry
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• 제50권4호
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• pp.308-315
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• 2007

오징어 가공 부산물인 오징어 내장을 효소제재와 같이 식품가공소재로 이용하기 위하여 오징어 내장의 endoprotease와 exopeptidase의 분포 특성에 대하여 살펴보았다. 오징어 내장은 조효소가 함유되어 있으리라 추정되는 단백질이 17.2%를 차지하였고, 또한, 이물질로 제거하여야 되는 조지방의 경우도 16.9%로 다량 차지하였다. 오징어 내장 조효소의 활성을 천연기질(azocasein)과 합성기질(LeuPNA 및 ArgPNA)로 나누어 살펴 본 결과 추출 용매(탈이온수, 1% NaCl, 1% KCl 및 1% NaCl-KCl 혼합용액)및 추출 시간(1-20시간)에 관계없이 전 조 효소가 동일 pH에서 천연기질의 분해활성에 비하여 상대적으로 합성기질의 분해활성(pH7.5)이 높아, 오징어 내장으로부터 효소를 분리하여 이용하고자 하는 경우 exopeptidase를 분리하여 이용하는 것이 적절하리라 판단되었다. 오징어 내장으로부터 exopeptidase를 분리하여 이용하고자 하는 경우 탈이온수를 이용하여 6-8시간 동안 추출하는 것이 가장 적절하리라 판단되었다. 오징어 내장 조효소의 최적 pH와 온도는 pH 7.5 및 $50-55^{\circ}C$범위로 판단되었다.

• Journal of Plant Biology
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• 제37권3호
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• pp.357-363
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• 1994

An expreiment with non-nodulating alfalfa (Medicago sativa L.) plants was designed to investigate the changes in protein contents and the activities of proteolytic enzymes during a regrowth period of 24 d. Shoot removal caused a depression of root growth and significantly reduced protein contents in roots. An initial decline of root proteins for the first 10 d was followed by a rapid recovery from d 11 to 24. The major increase of regrowing shoot weight occurred also from d 11. The activities of aminopeptidase and endoprotease slightly decreased in regrowing leaves, while protein contents remains stable after shoot removal. Roots exhibited source behaviour with a rapid increase of endoprotease activities for the first 10 d of regrowth; about a 370% increase over the initial level was observed. Increase in endoprotease activity in roots coincided with the time of protein remobilization after shoot removal, indicating the important role of endoproteases in protein degradation.

• 미생물학회지
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• 제24권2호
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• pp.119-126
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• 1986

A periplasmic endoprotease, named protease Pi, was purified to homogeneity from Escherkchia coli by conventional procedure with insulin as substrate. This enzyme degrades insulin and glucagon to trichloroacetic acid-soluble meterials, but shows little or no hydrolysis of bovine serum albumin, casein or globin. Its molecular weight was 110, 000 when determined by gel filtration on Sephacryl S-300 and was 105, 000 when estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Thus, it appears to be single polypeptide. This snzyme is metalloprotease, since it is completely inhibited by o-phenanthroline and can be activated by addition of divalent metal cations, such as $Mg^{2+}\;and\;Co^{2+}$. It is destinct from protease Ci, a cytoplasmic insulin degrading enzyme, since protease Pi is localized to the periplasm. Since protease Pi selectively degrades GTP cyclohydrolase I, it appears to play a role in the regulation of pteridine biosynthesis.

• 한국식품과학회지
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• 제29권6호
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• pp.1125-1130
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• 1997

효소 분해에 의해 HVP를 생산하는데 있어서 여러 가지 효소의 조합, 효소 첨가 순서, pH, 산세척 등이 가수분해에 미치는 효과를 검토하였다 Endoprotease으로서 Neutrase와 Alcalase를 혼합하여 사용하는 것이 Alcalase를 단독 사용하는 것 보다 가수분해도가 높았으며 exoprotease인 Flavourzyme을 이용하여 2차 가수분해함으로써 60%이상의 가수분해도를 얻을 수 있었다. 2차 가수분해 시 원심분리에 의해 미반응 불용 성분을 제거하는 것은 가수분해도에 큰 영향을 미치지 않았고, 1차 가수분해 후 2차 원심분리의 수세수를 원료 현탁에 재사용하였을 경우 가수분해도 및 단백질 회수율을 높일 수 있었다. Ca이온의 첨가에 의한 Neutrase의 안정화 효과는 가수분해도에 큰 영향을 미치지 않았다. 탄수화물 분해효소의 사용과 산세척의 반복에 의해 가수분해도와 생산물의 단백질 함량이 각각 증가함을 알 수 있었다. Endoprotease과 exoprotease을 별도로 각각 처리하기보다는 동시 처리하는 것이 가수분해에 효율적이었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.240.2-240
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• 1999

No Abstract, See Full Text

• 한국식품영양과학회지
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• 제34권8호
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• pp.1265-1273
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• 2005

새우 가공부산물(두부, 갑각 및 꼬리)을 이용한 멸치 액젓의 발효기간 단축 및 기호성 개선에 의한 고품질의 속성 멸치 액젓을 제조할 목적으로 새우 가공부산물을 마쇄 하고, 이를 멸치 마쇄물에 0$ \%$, 10$\%$, 20$\%$ 및 30$\%$를 각각 첨가한 다음 숙성 중 이들의 이화학적 특성, 효소학적 특성 및 수율 등을 검토하였으며, 아울러 이를 토대로 최적 숙성기간 및 첨가량의 구명을 시도하였다 새우 가공부산물의 첨가량에 관계없이 숙성 중 수분함량 및 pH의 경우 감소하는 경향을 나타내었고, 조단백질 함량, 휘발성염기질소 함량, 갈변도 및 수율의 경우 증가하는 경향을 나타내었으며, 염도의 경우 거의 변화가 없었다. 아미노질소 및 아미 노질소/총질소는 숙성 중 새우 가공부산물 0$\%$ 및 10$\%$ 첨가 제품의 경우 270일째까지 급격히 증가하는 경향을 나타내었으나, 새우 가공부산물 20$\%$ 및 30$ \%$ 첨가 제품의 경우 180일째까지 급격히 증가한 후 거의 변화가 없었다. 액젓 중의 endoprotease와 exoprotease 활성 및 gel filtration의 결과, 숙성기간이 경과함에 따라 멸치액젓은 저분자화 되었으며, 이러한 경향은 새우 가공부산물의 첨가량이 증가할수록 현저하였다. 새우 가공부산물 첨가 멸치액젓의 최적 숙성기는 무첨가 및 10$\%$ 첨가 제품의 경우 270일, 20$\%$ 및 30$\%$첨가 제품의 경우 180일로 판단되어, 새우 가공부산물의 경우 멸치액젓의 제조시 발효촉진제로 사용 가능하리라 판단되었다.

• Fisheries and Aquatic Sciences
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• 제15권3호
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• pp.197-202
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• 2012

This study examined and compared the exopeptidase and endoprotease activities of the hepatopancreas (HP) of cuttlefish, squid, and octopus species. The protein concentration in crude extract (CE) from octopus HP was 3,940 mg/100 g, lower than those in CEs from squid HP (4,157 mg/100 g) and cuttlefish HP (5,940 mg/100 g). With azocasein of pH 6 as a substrate, the total activity in HP CE of octopus was 31,000 U, lower than the values for cuttlefish (57,000 U) and squid (69,000 U). Regardless of sample type, the total activities of the CEs with azocasein as the substrate were higher at pH 6 (31,000-69,000 U) than at pH 9 (19,000-34,000 U). With L-leucine-p-nitroanilide (LeuPNA) of pH 6 as the substrate, the total activity of the HP CE from octopus was 138,000 U, higher than values from both cuttlefish HP (72,000 U) and squid HP (63,000 U). Regardless of sample type, the total activities of the CEs with LeuPNA as the substrate were higher at pH 6 (63,000-138,000 U) than at pH 9 (41,000-122,000 U). With LeuPNA as the substrate, the total activities of the CEs from octopus HP and cuttlefish HP were higher at pH 6 than at pH 9. However, there was no difference in total activity between pH 6 and 9 for squid HP CE with LeuPNA as the substrate. These results suggest that the octopus HP is superior to the cuttlefish HP and squid HP as a potential resource for extracting exopeptidases. Exopeptidases from octopus HP have potential industrial applications and their use might aid in reducing pollution related to the octopus industry.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1513-1520
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• 2023

Kex2 protease (Kex2p) is a membrane-bound serine protease responsible for the proteolytic maturation of various secretory proteins by cleaving after dibasic residues in the late Golgi network. In this study, we present an application of Kex2p as an alternative endoprotease for the in vitro processing of recombinant fusion proteins produced by the yeast Saccharomyces cerevisiae. The proteins were expressed with a fusion partner connected by a Kex2p cleavage sequence for enhanced expression and easy purification. To avoid in vivo processing of fusion proteins by Kex2p during secretion and to guarantee efficient removal of the fusion partners by in vitro Kex2p processing, P₁', P₂', P₄, and P₃ sites of Kex2p cleavage sites were elaborately manipulated. The general use of Kex2p in recombinant protein production was confirmed using several recombinant proteins.