• BMB Reports
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• v.43 no.6
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• pp.427-431
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• 2010

Cyt2Aa2 is a mosquito-larvicidal protein produced as a 29 kDa crystalline protoxin from Bacillus thuringiensis subsp. darmstadiensis. To become an active toxin, proteolytic processing is required to remove amino acids from its N- and C-termini. This study aims to investigate the functional role of amino acid residues on the N-terminal ${\beta}1$ and C-terminal ${\alpha}F$ of Cyt2Aa2 protoxin. Mutant protoxins were constructed, characterized and compared to the wild type Cyt2Aa2. Protein expression data and SDS-PAGE analysis revealed that substitution at leucine-33 (L33) of ${\beta}1$ has a critical effect on dimer formation and structural stability against proteases. In addition, amino acids N230 and I233-F237 around the C-terminus ${\alpha}F$ demonstrated a crucial role in protecting the protoxin from proteolytic digestion. These results suggested that ${\beta}1$ and ${\alpha}F$ on the Nand C-terminal ends of Cyt2Aa2 protoxin play an important role in the molecular interaction and in maintaining the structural stability of the protoxin.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.435-446
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• 2012

The present study identified volatile flavor components of Hanwoo longissimus muscle and other Korean foods (Doenjang, Chungukjang, sesame oil) and their traits were compared in relation with flavor precursors that include fatty acids and protein degradation products. Hanwoo longissimus muscle was purchased from a commercial abattoir while the other foods were sampled from three separate households. The results showed totals of 68 ($9.94{\mu}g/g$), 60 ($15.75{\mu}g/g$), 49 ($107.61{\mu}g/ml$) and 50 ($7.20{\mu}g/g$) volatile components for Doenjang, Chungukjang, sesame oil and Hanwoo beef longissimus, respectively (p<0.05). Aldehydes were the most predominant components in beef, but alcohols, acids and esters, and pyrazines are probably the major contributors to the flavor characteristics of other foods. SDS-PAGE revealed that beef longissimus muscle and Doenjang showed higher protein degradation than other foods which could be likely related to chiller ageing and ripening process. The total polyunsaturated fatty acids were approximately 50, 60, 41 and 5% for Doenjang, Chungukjang, sesame oil and beef longissimus muscle, respectively. Based on the mechanism(s) of generation of the volatile compounds and the chemical composition of each food sample, differences and traits of volatile flavor components among the four food types are likely due to fatty acid profiles, proteolytic activity and processing conditions. Aroma intense compounds like pyrazines and sulfur-containing compounds were limited in cooked beef in the current experimental condition (i.e., relatively low heating temperature). This suggests that higher heating temperature as in the case of roasting is needed for the generation of high aroma notes in meat. Furthermore, proteolytic activity and stability of fatty acids during ageing have a great influence on the generation of flavor components in cooked beef.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.207-211
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• 1976

Treated with various methods, body muscle of squid was cross section, stained by Van Gieson staining method, and observed microscopically to study on the state of thin layer of skin separated from meat. Results obtained were summarized as follows : 1. By general hot spring treatment were 1st. 2nd. and 3rd. layers of skin removed from squid muscle but 4th. not. 2. By boiling treatment was tissue of muscle fibre fissured largely toward the muscle fibre. 3. Sodium acetate treatment was superior to sodium nitrate, sodium sulfate and sodium tartrate treatment in the effect that the skin was separated from meat. Especially, concentrate solution of sodium acetate had the most excellent effect in the chemical reagent treatment. 4. By proteolytic enzyme treatment were 1st. 2nd. 3rd. and 4th. layers of skin removed all from squid muscle and the boundary fibre between skin and meat swelled in particular. 5. Two kinds of skin removing method, proteolytic enzyme treatment and sodium acetate treatment, were desirable to the actual processing.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.291-295
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• 2020

In order to increase the utilization of defatted sesame meal (DSM), a by-product of sesame oil production, the conditions of extraction of insoluble proteins from DSM by enzyme treatment were investigated. As a result of comparing the treatment results of proteolytic enzymes Alcalase, Flavorzyme, Neutrase, and Protamex with control, Protamex was effective in increasing the total solid and protein content. At the reaction conditions of Protamex (50 ℃, pH 6.0), the dosage of enzymes was appropriate for 1% of DSM and 3 h of enzyme reaction time. To improve the efficiency of enzymatic treatment, the protein content extracted increased as the heat treatment temperature increased, and slightly increased above 110 ℃. As a result of investigating the effect of the combination treatment of cell lytic enzyme (Tunicase) and protease (Protamex) on protein solubilization, it was most effective to treat the cell lytic enzyme after processing the protease. After heat treatment (110 ℃, 10 min), sequential treatment of Protamex and Tunicase increased the protein content by about 3.5 times (9.85→35.58 mg/mL) of the non-heated control and 2.2 times (15.83→35.58 mg/mL) of the heat treated control.

• Journal of Ginseng Research
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• v.46 no.5
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• pp.675-682
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• 2022

Background: Korean Red Ginseng (KRG) was reported to play an anti-inflammatory role, however, previous studies largely focused on the effects of KRG on priming step, the inflammation-preparing step, and the anti-inflammatory effect of KRG on triggering, the inflammation-activating step has been poorly understood. This study demonstrated anti-inflammatory role of KRG in caspase-11 non-canonical inflammasome activation in macrophages during triggering of inflammatory responses. Methods: Caspase-11 non-canonical inflammasome-activated J774A.1 macrophages were established by priming with Pam3CSK4 and triggering with lipopolysaccharide (LPS). Cell viability and pyroptosis were examined by MTT and lactate dehydrogenase (LDH) assays. Nitric oxide (NO)-inhibitory effect of KRG was assessed using a NO production assay. Expression and proteolytic cleavage of proteins were examined by Western blotting analysis. In vivo anti-inflammatory action of KRG was evaluated with the LPS-injected sepsis model in mice. Results: KRG reduced LPS-stimulated NO production in J774A.1 cells and suppressed pyroptosis and IL-1β secretion in caspase-11 non-canonical inflammasome-activated J774A.1 cells. Mechanistic studies demonstrated that KRG suppressed the direct interaction between LPS and caspase-11 and inhibited proteolytic processing of both caspase-11 and gasdermin D in caspase-11 non-canonical inflammasome-activated J774A.1 cells. Furthermore, KRG significantly ameliorated LPS-mediated lethal septic shock in mice. Conclusion: The results demonstrate a novel mechanism of KRG-mediated anti-inflammatory action that operates through targeting the caspase-11 non-canonical inflammasome at triggering step of macrophage-mediated inflammatory response.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.363-369
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• 1989

In this study, the biochemical characterization of strong proteolytic bacteria and their extracellular pretense isolated from fermented fish paste were experimented for the purpose of industrial large scale-production by accelerated fermentation. The results obtained were as follows: Among 4 strains isolated from fermented fish paste, B. subtilis p-4 and B. licheniformis p-5, which grow well at $40^{\circ}C$, pH 7.0 and $1\%$ of salt contents, were the best proteolytic bacteria and were shown $0.48hr^{-1}$, $0.49hr^{-1}$ of specific growth rate in TPY medium, respectively. Maximum enzyme activity of B. subtilis p-4 was 335n mole-Tyr/min.ml after 30 hrs and that of B. licheniformis p-5 was 300n mole-Tyr/min.ml after 28 hrs of shaking culture. Purified pretense produced by B. subtilis p-4 and B. licheniformis p-5 showed maximum activity at $50^{\circ}C$, pH 7.0 and molecular weight were estimated to be 18,000, 30,000 by sephadex G-100 gel filtration, respectively. These were supposed to be a kind of metal chelator sensitive neutral pretense from the result of high sensitivity against EDTA, o-phe-nanthroline and metal ions such as $Cu^{2+},\;Ni^{2+},\;Zn{2+}$.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.106-110
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• 1996

Bromelain(EC 3.4.22.4), the collective name for the proteolytic enzymes found in tissues of the plant family Bromeliaceae(pineapple), has been used as a tenderizing agent in food processing, and as an antiinflammatory agent in pharmaceuticals. In this paper, we describe the simple purification method of bromelain using Korean pineapple fruit. After removing contaminants at 30% saturation of ammonium sulfate, the supernatant obtained was treated again with ammonium sulfate to 80% saturation. Wit the above salt fractionation, partially purified bromelain could be obtained. To get highly purified bromelain, the previous 30% to 80% ammonium sulfate treated precipitate was dialyzed against 25mM sodium acetate buffer(pH 5.0) followed by passing through a CM- cellulose cation exchange column. Fruit bromelain was eluted as a major peak at 0.5~0.8M NaCI gradient. The present method is simpler with high wield than the traditional purification method-acetone treatment and several consecutive chromatographic processes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.342-349
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• 1983

This study was undertaken to ascertain food and nutritional evaluating data on the processing of fermented sea cucumber (Stichopus japonicus) entrails. In the experiment, the crude proteolytic enzyme from the entrails tissue of raw and fermented sea cucumber during the days of ripening was extracted. The optimal activity condition for the crude enzyme and the compositional changes of amino acid of the protein and free amino acid in the raw and fermented sample were also investigated. 1. Less than three kinds of proteolytic enzymes that each enzyme has optimal activity condition at pH 3.1 $50^{\circ}C$(A-enzyme), pH 5.7 $50^{\circ}C$(B-enzyme) and pH 7.7 $45^{\circ}C$(C-enzyme), respectively were believed to be exist in the entrails tissue of sea cucumber. 2. A-enzyme and C-enzyme were strongly inhibited with the increase of the salt concentration, and B-enzyme was activated at the 1% salt concentration and was inhibited above the 5% salt concentration. 3. The result of the effect of several salt ions on the proteolytic activity showed that A-enzyme was slightly inhibited in the presence of all salt ions added, B-enzyme was activated in the presence of the all salt ions except $Cu^{2+}$ and C-enzyme was activated in the presence of $Ca^{2+}$ and $Mn^{2+}$, and inhibited by $Cu^{2+}$, $Co^{2+}$ and $Mg^{2+}$. 4. When the effects of the ripening days on the proteolytic activity of the crude enzymes were analysed, the activity of the A-enzyme was slightly weakened with the lapse of the fermentation days, whereas the B-enzyme was not influenced by the fermentation days. 5. In the analysis of amino acid composition of the protein of the samples, the 8 days fermented sea cucumber entrails showed the diminution of all kinds of amino acid. Apparently diminished amino acids were arginine, alanine, glutamic acid, glycine, serine, valine, threonine and lysine etc., and methionine, histidine and isoleucine were slightly decreased. 6. In the analysis of free amino acid composition of the 8 days fermented sample, glutamic acid, aspartic acid, leucine and lysine were rich, while histidine, methionine, proline and tyrosine were poor. The most of free amino acids were increased during the fermentation procedure and especially in lysine, histidine, threonine, glutamic acid, methionine, valine and leucine.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.143-153
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• 1979

A study on tile processing of liquefied fish protein with a long self life and good solubility has been carried out for the effective utilization of sardine. The whole sadine was chopped, homogenized with same amount of water and then hydrolyzed by the addition of commercial proteolytic enzyme. The hydrolysate was centrifuged and the supernatant was decolorized with active carbon, desodorized by azeotropic distillation with toluene, xylene and cyclohexane. The liquefied sardine protein was then concentrated by rotary vacuum evaporator with the addition of starch. The use of $0.2\%$ commercial proteolytic enzyme to the weight of the whole sardine showed the optimum hydrolysis ratio at $55^{\circ}C$ for 4 hours. The liquefied sardine protein could be decolorized and also desodorized by the treatment with $15\%$ active carl]on at room temperature for 30 minuted. In the view point of lipid concentration and the solubility of the product, the liquefied sardine protein prepared by enzymic hydrolysis from the sardine protein concentrate was better than that prepared by enzymic hydrolysis from the whole sardine and sardine protein concentrate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.555-560
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• 2008

Amino acid transporters are essential for the growth and proliferation in all living cells. Among the amino acid transporters, the system L amino acid transporters are the major nutrient transport system responsible for the $Na^+$-independent transport of neutral amino acids including several essential amino acids. The L-type amino acid transporter 1 (LAT1), an isoform of system L amino acid transporter, is highly expressed in cancer cells to support their continuous growth and proliferation. 2-Aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) is a model compound for the study of amino acid transporter as a system L selective inhibitor. We have examined the effect and mechanism of BCH on cell growth suppression in HEp2 human head and neck squamous cell carcinoma. The BCH inhibited the L-leucine transport in a concentration-dependent manner with a $IC_{50}$ value of $51.2{\pm}3.8{\mu}M$ in HEp2 cells. The growth of HEp2 cells was inhibited by BCH in the timeand concentration-dependent manners. The formation of DNA ladder was not observed with BCH treatment in the cells. Furthermore, the proteolytic processing of caspase-3 and caspase-7 in the cells were not detected by BCH treatment. These results suggest that the BCH inhibits the growth of HEp2 human head and neck squamous cell carcinoma through the intracellular depletion of neutral amino acids for cell growth without apoptotic processing.