• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.147-153
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• 1983

To check the differences of the digestive enzymes by the bait habits and the proteolytic activities of the fissile extracts from the fish, omnivorous filefish (Navodon modestus), carnivorous cat shark (Scilliorhinus tarazame) and bloodsucking hag fish (Eptatretus burgeri) were sampled for this experiment. The activity of crude alkaline protease extracted from the muscle and the internal organs of the samples was determined with casein as substrate. The activity of the proteolytic enzymes showed remarkable differences by the organs of the fish. The optimum condition of the pretenses from the muscle revealed in range of pH 7.8-8.3, at $60-65^{\circ}C$, while those of the enzymes from the internal organs were at about pH 8.2, $45-55^{\circ}C$, but those of hag fish were at about pH 6.7, $45-55^{\circ}C$. The proteolytic activity of the enzyme of alimentary canal in filefish and in hag fish was 57 and 11 times stronger than that of muscle, respectively. The crude enzyme from the alimentary canal of file fish showed the strongest proteolytic activity in samples submitted and that of cat shark was the lowest. The activity of pancreatic alkaline protease in cat shark was 50 fold higher than that of muscle alkaline protease in the fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.216-224
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• 1983

This work was undertaken to obtain some characteristics of proteolytic enzyme of marine gastropods such as sea hare, Aplysia kurodai, top shell, Turbo cornutus, and abalone, Haliotis discus hannai. An influence of pH, temperature and some chemicals on proteolytic activity of the crude enzyme extracted from digestive tract of the samples was taken into account and the stability of the enzyme during the storage at low temperature was also discussed. In comparison of the activities of the crude enzyme from the samples to the optimum conditions, it was characterized that abalone has twice or the more times higher activities than the other two species of the gastropoda in the acid and weak acid region, while, in the alkaline region, sea hare has six or the more times higher acitivities than the other two species. The proteolytic activity was facilitated by $Mn^{2+}$, some reducing agents, EDTA and DTT, and inhibited by $Hg^{2+}$ and SDS, but the other chemicals were not significantly affected to the activity. The low temperature storage of the enzymes of sea hare and top shell at $0^{\circ}C\;or\;-20^{\circ}C$ was not affected to the enzymic activity under the optimum pH condition except in the alkaline region. On the other hand, the low temperature storage was brought about no significant effect on the activity of the enzymes extracted from abalone under the optimum condition of the weak acid region, but apparently influenced to the activity under the optimum condition of the acid and alkaline region.

• The Korean Journal of Zoology
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• v.32 no.1
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• pp.48-54
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• 1989

Several proteolytic activities and the level of and-trypsin in neoplastic tissues of human cervix and liver were compared to those in normal tissues to examine if any correlation exists between malignant behavior of the tumors and the changes in overall proteolytic capacity. Proteolysis against casein and insulin in cervix tumor was increased to 2-to 3-fold while that in liver tumor was reduced to one-tenth to one-half. By contrast, the level of anti-trypsin in cervix tumor was lowered to nearly one-tenth of that in normal tissues while the level rose to about 2-fold in malignant tissues of liver. On the other hand, the activities of plasmin-like protease and plasminogen activator were enhanced 10-20% over the activities in normals. These results suggest that the changes in proteolytic capacity are at least in part due to outbalance in either of proteolytic or its inhibitory activity over the other and occur distinctively to each tumor systems for their malignant behavior.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.803-806
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• 1993

The properties of proteolytic enzymes from the fruit of Broussonetia Kazinoki Siebold were investigated. The protease activity of the enzymes from the fruit of Broussonetia Kazinoki Siebold was 1.6 unit. The optimum temperature and pH of the enzymes were $60^{\circ}C$ and 7.0, respectively. The enzymes were stable at pH values from 6 to 8 for 1 hr. at $37^{\circ}C$ of incubation and also retained all activity after incubation for 1 hr. at $60^{\circ}C$. The enzyme preparations showed strong activities toward hemoglobin and collagen.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.385-389
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• 2019

In this study, proteolytic enzymatic treatment conditions for Korean red ginseng were examined to increase the extraction yield. Commercially available proteases were screened to obtain high protein and carbohydrate yield. The optimal dosage and reaction time for Alcalase, the chosen protease, were found to be 2.0% (w/w) and 1.5 h, respectively. Treatment with optimal conditions of Alcalase increased solid yield, total phenolic content and gensenosides content by 57.6, 81.8, and 33.8%, respectively, over levels in non-treated Korean red ginseng. Antioxidative activities evaluated by free radical scavenging activity, cation radical scavenging activity and reducing power were exactly similar between Alcalase-treated and non-treated extracts.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.25-30
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• 1986

The purposes of this study were to investigate enzyme components and its physiological activities of Sarcodon aspratus (Berk.) S. Ito which grows wildly in Korea, belonging to the family Thelephoraceae. The carpophores of the fungus was extracted with cooling distilled water and salted out by ammonium sulfate. The precipitate was purified by dialysing through visking tube against distilled water and then dissolved with pH 7.8 ammonia aqua, and the extract was filterated. The fraction of filtrate was obtained as light brown powder after lyophilization and determined proteolytic activity. Protease activity of Sarcodon aspratus (Berk.) S. Ito was about two-third of that of pepsin on casein by cup method. The proteolytic potency of this enzyme was found to be 500 unit/mg. This proved the efficacy of the mushroom when it was used as a folk medicine for treating indigestion of beef.

• Parasites, Hosts and Diseases
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• v.37 no.1
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• pp.39-46
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• 1999

As a preliminary study for the explanation of pathobiology of Neodiplostomum seoulense infection. a 54 kDa protease was purified from the crude extract of adult worms by sequential chromatographic methods. The crude extract was subjected to DEAE-Sepharose Fast Flow column, and protein was eluted using 25 mM Tris-HC1 (pH 7.4) containing 0.05. 0.1, 0.2 and 0.4 M NaC1 in stepwise elution. The 0.2 M NaCl fraction was further purified by Q-Sepharose chromatography and protein was eluted using 20 mM sodium acetate (pH 6.4) containing 0.05, 0.1. 0.2 and 0.3 M NaCl, respectively. The 0.1M NaCl fraction showed a single protein band on SDS-PAGE carried out on a 7.5-15% gradient gel. The proteolytic activities of the purified enzyme were specifically inhibited by L-trans-epoxy-succinylleucylamide (4-guanidino) butane (E-64) and iodoacetic acid. The enzyme, cysteine protease. showed the maximum proteolytic activity at pH 6.0 in 0.1 M buffer, and degraded extracellular matrix proteins such as collagen and fibronectin with different activities. It is suggested that the cysteine protease may playa role in the nutrient uptake of N. seoulense from the host intestine.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.46-60
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• 2023

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55℃/3 h) and thermolysin (pH 7.5/37℃/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.594-599
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• 2001

This study was attempted to isolate and identify the strain revealing high angiotensin converting enzyme (ACE) inhibitory activity from various soy fermented foods, i.e. meju, soybean paste and soy sauce. Forty-two strains with morphologically different characteristics were selected and the ACE inhibitory and proteolytic activities were examined. Of the strains tested, SS103 which was isolated from soy sauce showed the highest ACE inhibitory and proteolytic activities and was finally selected for further studies. The SS103 strain showed motility, rod form and ellipsoidal spores. The shape of colonies on the agar media was irregular, mucoidal and surface dull. The strain could grow under aerobic conditions of pH 5~9 and 10~$50^{\circ}C$. Main cellular fatty acid was $C_{15:0}$ anteiso, $C_{17:0}$ cis and $C_{17:0}$ iso, which was 33.9%, 18.8% and 16.5%, respectively. Based upon these morphological, biochemical and cultural properties, SS103 was identified as a Bacillus subtilis. Optimum cultural condition of Bacillus subtilis SS103 was pH 8.0, $37^{\circ}C$ and 48 hr.48 hr.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.409-418
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• 1995

As a part of studying the function and structure of the mudflat environment of the Yellow Sea, seawater samples in the overlying waters of sediment near Daesan were collected every hour on March 29 (spring tides) and on April 5 (neap tides), 1995 to study the diurnal distribution of aerobic saprophytic bacteria and their extracellular enzyme activities. The diurnal distribution of aerobic saprophytic bacteria ranged from 1.0 X $10^{2}$ to 7.07 X $10^{3}$ cfu /ml at spring tides and from 1.0 X $10^{2}$ to 8.3 X $10^{3}$ cfu /ml at neap tides. The diurnal variations of aerobic saprophytes at the suface waters were greater than those of middle and bottom waters. However, th diurnal fluctuation of saprophyte numbers at spring tides showed no significant difference compared with that at neap tides. The numbers of three physiological groups of aerobic hacteria (proteolytic, lipolytic and amylolytic bacteria) at the surface waters during spring and neap tides were lower than those at the middles and bottom waters. The diurnal variations of five extracellular enzyme activities at the surface waters during the survey period showed lower values than those at the middle and botton waters. Among the measured extracellular enzyme activities, phosphatase showed the highest. However, the activities of amylase, chitinase and cellulase showed a similar tendency.