• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.323-330
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• 1995

Protease activity was identified in crude extracts of Pnrqgonimw westermnni eggs which were purified from infected dog lungs, isolated on 14 weeks after metacercarial challenge. The eggs were used after removing possibly contaminated host or worm tissues on their shell surfaces. In the crude egg extracts, high proteolytic activities against carboBfrb enzoyl - ph enylalanyl - arginyl-4- methoxy- β- naphthylamide (Cbz - phe - arg- MNA) and Azocoll were detected whereas those against succinyl-alanyl-propyl-phenylalanyl-p- nitroanilide (Suc-ala-pro-phe-pNA) were not revealed. The eVe eBdlibited the maximal activity at pH 6. Its activity was inhibited by specific cysteine protease inhibitors, 105 M I- trans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and 1 mM iodoacetamide (LAA) while potentiated by 6.5-fold in the presence of 2.5 mM dithiothreitol (DTT) . When the enzyme was purified partially by Sephacryl S-300 High Resolution gel filtration, it migrated as a single homogeneous band at 35 kDa. The 35 kDa cysteine protease has been recognized neither in the metacercariae nor in the adult. These findings indicated the presence of at least one protease of cathepsin family in immature eggs of f westernani.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.614-627
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• 2020

During the course of this trial, our team assessed the influence of protease upon the growth performance, the nutrient digestibility, and the expression of growth-related genes and amino acid transporters within the liver, muscle, and small intestines of broilers. During the first step, our team allocated 600 broilers into four dietary treatments for a period of 35 days in order to measure the growth performance and nutrient digestibility of the broilers selected. The separate treatments contained 10 replicates (15 birds per replicate). The treatments were composed of: 1) CON, basal diet; 2) T1, basal diet + 0.03% protease; 3) T2, basal diet + 0.06% protease; and 4) T3, basal diet + 0.09% protease. Next, the broiler chick sample tissue was harvested from the CON and T3 groups in order to conduct gene expression analysis following the feeding trials the broilers underwent. Our team discovered that the broilers fed protease diets possessed increased body weight and an average daily gain, but conversely, had lower feed conversion ratios when their dietary protease levels increased from 0% to 0.09% (p < 0.05). Additionally, significant linear improvements were identified among the nutrient digestibility of dry matter, crude protein, energy, and amino acids within broilers supplied with protease diets when contrasted and compared with broilers supplied with the basal diet (p < 0.05). In addition, the gene expression of the genes IGF1, IGF2, GH, and LEP in the liver, and the genes MYOD1 and MYOG in the breast muscles, was significantly increased after broilers were fed with a protease diet as compared to broilers that subsisted on a basal diet (p < 0.05). Protease supplementation also raised the expression levels within these amino acid transporters: SCL6A19, SLC7A1, SLC7A7, SLC7A2, SLC7A6, SLC7A9, and SLC15A1, located in the small intestine, when compared to the basal diet (p < 0.05). Our results suggest that protease supplementation in their diet improved the growth performance of broilers via an increase in the expression growth-related genes within broiler liver and muscle tissue. In addition, protease supplementation enhanced broiler digestibility via the upregulation of amino acid transporter expression within the small intestine.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.133-142
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• 1998

A 40 kDa cysteine protease was purified from the crude extract of adult worms of GMnnophalloines seoi by two consecutive steps: Sephacryl S-200 HR and DEAE- Sephacel chromatography. Enzyme activities were completely inhibited by cysteine protease inhibitors, L-lorans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and iodoacetic acid, strongly suggesting that the purified enzyme belongs to the cysteine family of proteases. The enzyme was maximally acive at pH 4.5 in 0.1 M of buffer, and its activity was greatly potentiated in the presence of 5 mM dithiothreitol. The protease degraded macromolecules with differential capabilities : it degraded extracellular matrix proteins, such as collagen and fibronectin, with a stronger activity against collagen than fibronectin . However, the enzyme digested hemoglobin and human immunoglobulins only slightly. leaving them nearly intact after an overnight reaction. Our results suggest that the cysteine protease of G. seoi adults is potentially significant in the nutrient uptake from the host intestine.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.193-200
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• 1997

In order to manufacture the low salt and functional Kochujang, salt amount was reduced to 6% and chitosan was added to 0.25% to the Kochujang preparation. The contents of ash, moisture, crude fat and crude protein in Kochujang were not affected by the reduced salt concentration and chitosan addition. pH and titratable acidity were not significantly changed by the addition of chitosan. Ethanol content was higher in 6% salt Kochujang tan in 9% salt Kochujang and decreased by the addition of chitosan. Reducing sugar content was lower in 6% salt Kochujang than in 9% salt Kochujang and increased by chitosan addition. $\alpha$-Amylase activity was slightly inhibited by the addition of chitosan, however, $\beta$-amylase, acidic protease and neutral protease activities were not affected. Amino nitrogen and ammonia nitrogen contents were higher in 6% salt Kochujang than in 9% salt Kochujang, but ammonia nitrogen production was significantly decreased by chitosan addition. Also the growth of bacteria and yeasts were slightly inhibited by the addition of chitosan. From the above results we concluded that 0.25% chitosan was the good concentration to prepare the low salt and functional Kochujang.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.260-265
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• 2003

Transglutaminase (TG) was prepared from Streptomyces mobaraensis to improve texture and self-life of food. In preliminary experiments, texture of the dough was not improved due to the interference in microbial TG reaction by proteases present in the crude enzyme. Among the cation exchange resins tested for the removal of proteases, MonoPlus S 100 was the most efficient. Further purification steps with a quaternary ammonia salt resin and gel permeation chromatography effectively removed proteases from crude enzyme. Molecular weight of purified enzyme was about 38,000 on SDS-polyacrylamide gel electrophoresis. Farinograph data showed the addition of purified enzyme to wheat flour gave higher stability and lower weakness values those that of crude enzyme.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1063-1076
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• 2022

Two experiments were conducted to determine the effect of Hermetia illucens larvae (HIL) as protein and protease on growth performance, blood profiles, fecal microflora, and gas emission in growing pig. In experiment 1, the seventy-two crossbred growing pigs ([Landrace × Yorkshire] × Duroc) with an initial body weight (BW) of 27.98 ± 2.95 kg were randomly allotted to one of four dietary treatments (3 pigs per pen and 6 replicates pen per treatments). The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two diets (Poultry offal diets and HIL diets) without or with supplementing protease. The poultry offal in basal diet has been replaced by HIL. In experiment 2, the four crossbred growing pigs ([Landrace × Yorkshire] × Duroc) with an initial BW of 28.2 ± 0.1 kg were individually accepted in stainless steel metabolism cages. The dietary treatments included: 1) PO- (PO-; poultry offal diet), 2) PO+ (PO- + 0.05% protease), 3) HIL- (3% PO of PO- diet was replacement 3% HIL), 4) HIL+ (HIL- + 0.05% protease). In experiment 1, From weeks 0 to 2, average daily gain (ADG) and feed efficiency (G:F) were significantly increased in the PO diet group compared with the HIL group. From weeks 2 to 4, ADG and G:F were higher for protease group than for non-protease group. At weeks 2 and 4, the PO diet group had lower blood urea nitrogen (BUN) levels than HIL diet group. In experiment 2, crude protein (CP) and nitrogen (N) retention were decreased by HIL diet at weeks 2 and 4. The fecal microflora and gas emission were not affected by HIL and protease. The HIL diet showed lower CP digestibility than PO diet and total essential amino acids digestibility tended to higher in PO diet than HIL diet. In summary, the present study revealed that replacement of the PO protein with the HIL protein and the additive of protease in growing pig diets during the overall experimental period had no negative effect.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.157-163
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• 2009

This study was conducted for the isolation, purification, and characterization of a protease from Korean pear, to see its proteolytic activity on chicken actomyosin and to find the optimum pH and temperature of activity on chicken actomyosin. The protease was isolated from crude extract of Korean pear by ammonium sulfate precipitation. Further purification was done by DEAE-Sepharose ion-exchange chromatography, Mono-Q and Mini-Q column chromatography. The purified enzyme gave a single protein band on SDS polyacrylamide gel electrophoresis and the molecular weight was found to be 38 kDa. The specific activity of purified enzyme was 34,907 unit/mg with 25 fold purification and the yield was 2%. The purified enzyme incubated with chicken actomyosin showed high activity. The optimum pH and temperature for enzyme activity on chicken actomyosin were 6.5 and $70^{\circ}C$, respectively. A protease was purified from Korean pear for the first time and characterized. It was found to be promising for meat tenderization.

• Journal of Pharmaceutical Investigation
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• v.18 no.3
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• pp.125-131
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• 1988

This study was undertaken to investigate the proteolytic enzyme from Neungee mushroom [Sarcodon aspratus (Berk) S. Ito]. The proteolytic activity of Neungee was higher than other several edible mushrooms under various pHs. The potency of proteolytic enzyme of Neungee was same as the digestive drugs containing protease. So the proteolytic activity of the enzyme was increased in neutral or weak alkaline pH, whose characteristics would be alkaline protease. The specific activity of the purified enzyme obtained by using Tris acryl CM-cellulose ion exchange increased 20 times as compared with that of the crude extract. The proteolytic enzyme was stable at room temperature, but decomposition was fast when incubated at higher temperature more than $40^{\circ}C$. The half life of the enzyme was longest in neutral pH and rate constant was increased in acidic or alkaline solution.

• Microbiology and Biotechnology Letters
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• v.1 no.2
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• pp.93-98
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• 1973

The acid protease was isolated from the culture broth of the Penicillum sp. grown in the wheat bran media. 'quot;The crude purification of this enzyme was carried out by extraction with distilled water and precipitated with saturated ammonium sulfate. " The activity of this enzyme was found to be very strong by Folin′s colorimetric method. The results were as follows. 1. The optimum pH of the enzyme activity was at 3.0 and its optimum temperature was 5$0^{\circ}C$. 2. Although the enzyme activity to hydrolyze casein was maximal at 5$0^{\circ}C$, its activity decreased rapidly by about 50％, treated at 5$0^{\circ}C$ for 30 min. When treated at 4$0^{\circ}C$ for 60 min, the enzyme activity decreased to 75％ of original value and did not decrease any more. 3. The enzyme was stable at pH 2.0 to 6.0. 4. This enzyme activity was not effected by metal ions; C $d^{＋＋}$, Z $n^{＋＋}$, $Co^{＋＋}$, H $g^{＋＋}$, M $n^{＋＋}$, P $b^{＋＋}$, $Mg^{＋＋}$, L $i^{＋}$, C $u^{＋＋}$, $Ba^{＋＋}$, A $g^{＋}$, $Al^{＋＋＋}$, $Ca^{＋＋}$, F $e^{＋＋}$, and F $e^{＋＋}$ 5. Also, it was not effected by treatemnt of EDTA.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.193-199
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• 2003

In order to investigate the meat tenderizing effects of pear, pineapple and kiwifruit, crude protease was prepared from each fruit and treated with actomyosin in a single manner or mixed type in several combination. Actomyosin was incubated with various proteases for 24 hrs under three different pH condition, and its degrading performance was evaluated by the SDS-PAGE. Pear extract showed an active degrading activity for actomyosin at pH 5.3 and 7.0. But, little actomyosin degradation was observed at pH 8.0. Actomyosin was strongly degraded by the treatment of protease from pineapple at all different pHs(5.3, 7.0 and 8.0). Kiwifruit protease extract has shown actomyosin degradation activity 1hr after treatment at pH 5.3 and pH 7.0. Meanwhile, the mixture of pear and pineapple extracts(l:l, w/w) showed much more degradation than the results of singular manner treatment at pH 5.3 and 7.0. When the pear protease was mixed with kiwifruit protease(l:l, w/w), the performance of actomyosin degradation was similar to the results of each single protease treatment. When the mixture was made of pineapple and kiwifruit extracts, actomyosin degradation was almost the same as the result of treatment of pineapple protease only. When those three proteases were mixed together(l:l:l, w/w/w), actomyosin degrading activities was in time dependent manner at pH 5.3. In summary, pear protease can be used potentially as a meat tenderizer when it was mixed with pineapple or kiwifruit rendering proper tenderization of the meat.