• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.04a
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• pp.184.4-184
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• 1976

Cheese제조에 이용할 수 있는 우유응고효소를 미생물 발효로써 생산할 목적으로 먼저 자연계에서 균주를 분리 선정하였다. 토양 및 메주로부터 분리한 200주의 미생물 가운데 약 50주가 2시간 이내에 curd를 형성하였으나 대부분이 proteolytic activity가 너무 커서 그대로는 이용할 수가 없음을 알았다. 그중에 유망한 균주 하나를 pH를 달리하여 배양해 보았더니 acid쪽에서 neutral보다 clotting/proteolytic ratio가 1.7배나 증가함을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.884-888
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• 2003

Proteolytic enzymes are used for meat tenderization, an important process with regard to consumer preference. The proteolytic enzyme, IVRIN was isolated from the plant Cucumis pubescens W and its effect on physico-chemical properties and lipid profile of thigh and breast muscle of culled, desi and broiler birds was studied. Fifty-gram meat was treated with IVRIN containing 32.5 mg enzyme protein at $60^{\circ}C$ for 20 min. The pH of IVRIN treated meat was decreased significantly (p<0.01) and the effect was more pronounced in breast than thigh muscle. The water holding capacity (WHC) was increased significantly (p<0.01) in broiler as compared to desi and culled bird, and in breast compared to thigh muscle. IVRIN failed to produce any impact on muscle fiber diameter (MFD). The MFD of desi was significantly higher (p<0.01) than broiler and culled birds. The total lipid concentration in thigh and breast muscle of desi was lower (p<0.01) than broiler and culled birds, latter being similar in this respect. The cholesterol content was lower (p<0.01) in breast than thigh muscle, in broiler than desi and culled and in IVRIN treated than untreated meat samples. The phospholipid concentration was unaffected by IVRIN. Broiler and culled birds exhibited more phospholipid content than desi birds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.557-568
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• 1995

Proteolytic properties of enzymes from the muscle and viscera of anchovy have been examined. Cathepsin L, chymotrypsin, and trypsin showed similar Km values for casein. However, they had higher Km values for myofibrillar proteins than those for casein. The $k_cat$ of cathepsin L and chymotrypsin for myofibrillar proteins were higher than that of trypsin, and also cathepsin L and chymotrypsin caused higher hydrolysis in myofibrillar proteins of anchovy and yellowtail. In the presence of sodium chloride$(0-25\%)$, proteolytic activity for myofibrillar proteins from yellowtail was higher than that for casein. Proteolytic activity was decreased with the increase of sodium chloride concentration. Cathepsin L had been less affected by NaCl concentration and temperature on the hydrolysis of myofibrillar proteins than chymotrypsin and trypsin. Cathepsin L and chymotrypsin were move responsible to the autolysis of muscle proteins from fish than trypsin.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.285-291
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• 1984

In making liquid yoghurt, the influences of proteolytic ability of lactic acid bacteria on acid production and on protein stability were investigated. L. bulgaricus CH-2, L. helviticus IAM 1042 and L. jugurti 3048 showed a comparatively high proteolytic activity in milk, while L. casei YIT 9018 did not show any marked proteolysis. Starter organisms having high proteolytic ability showed more rapid growth and acid production than those having low ability in milk. The most active proteolysis occurred during logarithmic growth phase of yogurt organisms, and most of the proteolysis took place in the first 24-48 hrs of incubation. Highly proteolysed yogurts made by L. bulgaricus CH-2, L. jugurti 3048, L. helviticus IAM 1042, L. acidophilus L-54 and L. casei 3012 had low protein solubility at pH 3.5 and had much protein precipitates during storage of product, but those having little protein hydrolysates made by L. casei YIT 9018 or artificial acidification showed no precipitation during keeping.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1581-1588
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• 2018

The growth of lactic acid bacteria (LAB) generates a high number of metabolites related to aromas and flavors in fermented dairy foods. These microbial proteases are involved in protein hydrolysis that produces necessary peptides for their growth and releases different molecules of interest, like bioactive peptides, during their activity. Each genus in particular has its own proteolytic system to hydrolyze the necessary proteins to meet its requirements. This review aims to highlight the differences between the proteolytic systems of Streptococcus thermophilus and other lactic acid bacteria (Lactococcus and Lactobacillus) since they are microorganisms that are frequently used in combination with other LAB in the elaboration of fermented dairy products. Based on genetic studies and in vitro and in vivo tests, the proteolytic system of Streptococcus thermophilus has been divided into three parts: 1) a serine proteinase linked to the cellular wall that is activated in the absence of glutamine and methionine; 2) the transport of peptides and oligopeptides, which are integrated in both the Dpp system and the Ami system, respectively; according to this, it is worth mentioning that the Ami system is able to transport peptides with up to 23 amino acids while the Opp system of Lactococcus or Lactobacillus transports chains with less than 13 amino acids; and finally, 3) peptide hydrolysis by intracellular peptidases, including a group of three exclusive of S. thermophilus capable of releasing either aromatic amino acids or peptides with aromatic amino acids.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.225-230
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• 1983

The proteolytic bacteria were isolated from the market foods such as ground beef, cooked shrimp meat, perch fillet, oyster meat, beef with textured vegetable protein and fish digest distributed at supermarket in Corvallis, Oregon, U.S.A. Two hundred and twenty-eight strains($30.8\%$) have proteolytic activity from 740 strains isolated from the examined samples and the strongest proteolytic strain among them was identified as a Streptococcus sp. Its maximum growth was showed at about 6 hours culture at $37^{\circ}C$ with shaking incubator in the medium added $0.15\%$ potassium phosphate monobasic and $0.4\%$ potassium phosphate dibasic, while the strongest activity of its extracellular protease was observed after 7 hours culture. The exoenzyme produced by the Streptococcus sp. was observed as a metal chelator sensitive protease, which are strongly inhibited by EDTA and o-phenanthroline but not affected by phenylmethylsulfonylfluoride and p-hydroxymercuribenzoate.

• Journal of Life Science
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• v.25 no.4
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• pp.385-389
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• 2015

In this study, it is reported that a large polyprotein can be stoichiometrically cleaved by the use of caspase-3-dependent proteolysis. Previously, it has been shown that the proteolytic IETD motif was partially processed when treated with caspase-3, while the DEVD motif was completely cleaved. The cleavage efficiency of the DEVD-based substrate was approximately 2.0 times higher than that of the IETD substrate, in response to caspase-3. Based on this, 3 protein genes of interest were genetically linked to each other by adding two proteolytic cleavage sequences, DEVD and IETD, for caspase-3. Particularly, glutathione-S transferase (GST), maltose binding protein (MBP), and red fluorescent protein (RFP) were chosen as model proteins due to the variation in their size. The expressed polyprotein was purified by immobilized metal ion affinity chromatography (IMAC) via a hexa-histidine tag at the C-terminal end, showing 93 kDa of a chimeric GST:MBP:RFP fusion protein. In response to caspase-3, cleavage products, such as MBP:RFP (68 kDa), MBP (42 kDa), RFP (26 kDa), and GST (25 kDa), were separated from a large precursor GST:MBP:RFP (93 kDa) via SDS-PAGE. The results obtained from this study indicate that a multi-protein can be stoichiometrically produced from a large poly-protein by using proteolytic recognition motifs, such as DEVD and IETD tetra-peptides, for caspase-3.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1191-1195
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• 1997

This study was conducted to investigate the proteolytic properties of saewoojeot (salted and fermented shrimp) on various meat proteins. NaCl content was decreased less than 2% by electrodialysis. As electrodialysis time was passed, the protease activity was increased. The proteolytic activity of crude protease on muscle proteins of beef, pork, chicken was analyzed by SDS-PAGE. Crude enzyme easily degradated both heat-denatured and native meat proteins. Protein degradation was rapidly occurred within 5 min and most all myofibrilar protein was disappeared. Heat-denatured chicken meat (100%) was most easily degraded than heat-denatured pork meat (47%) and beef meat (31%).

• Food Science of Animal Resources
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• v.41 no.4
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• pp.589-607
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• 2021

Meat proteolytic systems play a crucial role in meat tenderisation. Understanding the effects of processing technologies and post-mortem storage conditions on these systems is important due to their crucial role in determining the quality characteristics of meat and meat products. It has recently been proposed that tenderisation occurs due to the synergistic action of numerous endogenous proteolytic systems. There is strong evidence suggesting the importance of μ-calpain during the initial post-mortem aging phase, while m-calpain may have a role during long-term aging. The caspase proteolytic system is also a candidate for cell degradation in the initial stages of conversion of muscle to meat. The role of cathepsins, which are found in the lysosomes, in post-mortem aging is controversial. Lysosomes need to be ruptured, through aging, or other forms of processing to release cathepsins into the cytosol for participation in proteolysis. A combination of optimum storage conditions along with suitable processing may accelerate protease activity within meat, which can potentially lead to improved meat tenderness. Processing technologies such as high pressure, ultrasound, and shockwave processing have been reported to disrupt muscle structure, which can facilitate proteolysis and potentially enhance the aging process. This paper reviews the recent literature on the impacts of processing technologies along with post-mortem storage conditions on the activities of endogenous proteases in meat. The information provided in the review may be helpful in selecting optimum post-mortem meat storage and processing conditions to achieve improved muscle tenderness within shorter aging and cooking times.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.2
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• pp.71-75
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• 2010

To investigate the intestinal absorption of a fibrinolytic and proteolytic lumbrokinase extracted from Eisenia andrei, we used rat everted gut sacs and an in situ closed-loop recirculation method. We extracted lumbrokinase from Eisenia andrei, and then raised polyclonal antibody against lumbrokinase. Fibrinolytic activity and proteolytic activity in the serosal side of rat everted gut sacs incubated with lumbrokinase showed dose- and time-dependent patterns. Immunological results obtained by western blotting serosal side solution using rat everted gut sacs method showed that lumbrokinase proteins between 33.6 and 54.7 kDa are absorbed mostly by the intestinal epithelium. Furthermore, MALDI- TOF mass spectrometric analysis of plasma fractions obtained by in situ recirculation method confirmed that lumbrokinase F1 is absorbed into blood. These results support the notion that lumbrokinase can be absorbed from mucosal lumen into blood by oral administration.