• Fisheries and Aquatic Sciences
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• v.3 no.3_4
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• pp.188-194
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• 2000

A protease purified from hepatopancreas of shrimp, Penaeus japonicus, had maximum activity at $70^{\circ}C$ and in neutral and alkaline pH ranges. Specific activity at optimum reaction condition of the protease was estimated to be approximately 12 U/mg/min. The protease was stable in neutral and alkaline pH ranges and activity was retained after heat treatment at $50^{\circ}C$ for 30 min. Apparent $K_m$ and $V_{max}$ value against casein substrate were estimated to be $0.29\%$ and $7.8see^{-1}$, respectively, and those against N-CBZ-L-tyrosine p-nitropheny1 ester (CBZ­Tyr-NE) were 0.38 mM and $2,400 see^{-1}$, respectively. The N-termina1 sequence of the protease showed high homology to the trypsin from same species and the proteases from shrimp. Myosin heavy chain (MHC) from shrimp tail meat was the most susceptible to the protease and actin/tropomyosin were degraded progressively during 4 hr incubation, but to a lesser degree than MHC.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.218-225
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• 1999

A protease without tryptic and chymotryptic activities was purified from the hepatopancreas of shrimp, Penaeus orientalis, using Q-Sepharose ionic exchange, benzamidine Sepharose-6B affinity, Mono-Q, and gel chromatography. Molecular weight (M.W.) of the protease was estimated to be 27kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS­PAGE). The amino acid composition of the protease was different from that of protease from P. japonicus or trypsin from P. orientalis. The protease was completely inhibited by benzamidine, $N\alpha-p-tosyl-L-lysine$ chloromethyl ketone (TLCK), and phenylmethylsulfonyl fluoride (PMSF) and was not affected by leupeptin, pepstatin, N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), iodoacetate, and ethylenediamine tetra acetate (EDTA). The enzyme did not have any activity against Na-benzoyl-DL-arginine p-nitroanilide (BAPNA) or N-benzoyl-L-tyrosine ethyl ester (BTEE) which are specific substrates of trypsin and chymotrypsin, respectively. However, the protease showed hydrolytic activity for a carboxyl terminal of Tyr, Trp, Phe, Glu, and Cys.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.201-208
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• 1998

A protease, which had no tryptic and chymotryptic activity, was purified from the hepatopancreas of shrimp, P. japonicus, through ammonium sulfate fractionation, Q­Sepharose ionic exchange, benzamidine Sepharose 6B affinity, and Sephacryl S-100 gel chromatography. Molecular weight (M.W.) of the protease was estimated to be 24 kDa by gel filtration and showed a single peptide band by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The protease had a low ratio of acidic to basic amino acids, which is different with pro teases from marine animals. The enzyme was partially inhibited by benzamidine, tosyl-L-lysine chioromethyl ketone (TLCK), phenylmethylsulfonyl fluoride (PMSF), soybean trypsin inhibitor (SBTI), and pepstatin. The enzyme did not have any activity against benzoyl-D,L-arginine p-nitroanilide (BAPNA) or benzoyl-L-tyrosine ethyl ester (BTEE) which is a specific substrate of trypsin and chymotrypsin, respectively. However, the enzyme showed activity forward N-CBZ-L-tyrosine p-nitrophenyl ester (CBZ-Tyr-pNE), N­CBZ-L-tryptophan p-nitrophenyl ester (CBZ-Trp-pNE), and N-CBZ-L-proline p-nitrophenyl ester (CBZ-Pro-pNE). The protease did not showed tryptic and chymotryptic activity, which was not reported in shrimp hepatopancreas.

• Journal of Nutrition and Health
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• v.19 no.6
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• pp.363-373
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• 1986

This study was devised to elucidate whether soused shrimp exhibits a digestive action on boiled pork meats. and the mechanism by which sousing with a high concentration of sodium chloride preserves nutrients in foods for a prolonged pe\ulcornerriod. Protease was isolated from soused shrimp using a combination of ammonium sulfate fractionation. DEAE - cellulose ion exchange chromatography and gel filtra\ulcornertion. The isolated protease had specific activity of 1.560 units. 210 purification fo\ulcornerld with an yield of 38%. Its optimum pH and temperature were 8.0 and $43^{\circ}C$ respectively. The molecular weight of the enzyme was 35.000. The Km value of the enzyme for casein was 1.6 x $10^{-6}$ M The e=yme required the presence of cu\ulcornerpric ion to exhibit its full activity. Eighty eight percent of the enzyme activity was in\ulcornerhibited by 3.5M NaCI showing a reversibly linear decrease of the enzyme activity as NaCI concentration increased. The nature of the inhibition by NaCl was rever\ulcornersible and noncompetitive. The protease activity in soused shrimp was well preser\ulcornerved with the elapse of time at least in part due to NaCI induced suppression of autodigestion. The enzyme was denatured by acid easily. i.e. 1% of the original activity remained after staying at pH 2 for 10 minutes. which is within the norm\ulcorneral range of pH of the human stomach. Soused shrimp was observed to be one of those containing the highest protease activity compared with the other soused foo\ulcornerds such as soused oyster. squid. clam. and Pollack intestine with respect to spec\ulcornerific activities of dialized 1:4 whole homogenates(w/v) in 5 mM sodium phospha\ulcornerte - 2.4 mM j3 - mercaptoethanol buffer. pH 8.0. Casein and boiled meats including pork, beef, and chicken appeared to be the good substrates for the protease. Casein was the best. Therefore. the ingestion of boiled meats including pork together with soused sh\ulcornerrimp would help digestion of boiled pork in human not only by increasing appe\ulcornertite also by the direct proteolytic digestion of boiled meats by soused shrimp to\ulcorner some extent. And a high concentration of sodium chloride inhibited the protease activity reversibly in a remarkable degree, which ensued in a significant retardat\ulcornerion of autodigestion of protein in foods by proteases, and hereby contributed to the preservation of foods for an extended period.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.117-126
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• 2010

A chitinase (CHT) and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017, with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by $Mn^{2+}$ and $Cu^{2+}$, and PRO was inhibited by most tested divalent metals and EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were pH 5, $50^{\circ}C$, pH 5-7, and <$50^{\circ}C$, and pH 9, $40^{\circ}C$, pH 5-11, and <$40^{\circ}C$, respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is an SDS-resistant protease and probably has a rigid structure. The $4^{th}$-day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content ($196{\pm}6.2\;{\mu}g$ of gallic acid equiv./ml). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it is effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.629-634
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• 2000

The effects of gamma irradiation on changes of chemical compounds of fermented shromp with low salt were studied. The shirmp was salted NaCl concentration of 10%, 15% and 20%, and irradiated at 0, 2.5, 5.0, 7.5 and 10.0kGy. Amino nitrogen (AN), volatile basic nitrogen (VBN), trimethylamine (TMA) and neutral protease acivity were examined during ferentation at 15$^{\circ}C$. A sample with 30% salt concontration was also prepared as a control. The initial contents of AAN, VBN, TMA and protease acitivity were not affected by gamma irradiation. The contents of AN, VBN and TMA were incteased with fermentation period. But, the more increased NaCl concentrations and the higher irradiation dose, the loss increased content of chemical compounds and protease activity were found. Protease was increased until 4~5 weeks and then decreased gradually. The results showed that the chemical compounds and protease activity of salted abd fermeted shrimp prepared with 15% NaCl contentration and 10 kGy irradiation dose, or 20% and 5 kGy or higher were maintained the appropriate level of quality up to 10 weeks of storage compared with the control.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.264.2-265
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• 1998

• 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%).

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.760-763
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• 2001

Five commercial salt-fermented shrimps contained 29.8~48.3% of salt 3.5%~7.3% of total nitrogen and 0.3~0.7g/100g of amino-nitrogen respectively. The average peptide length(APL) of five commercial salt-fermented shrimps ranged from 10.1 to 15.0. Sample B and E showed longer APL than the others with the values of 15.0 and 14.4 respectively. Protease activity showed the large differences in five samples from 17 unit to 232 unit ; sample C showed the highest protease activity with 232 unit while sample D and E were relatively lower with 17 unit and 18 unit respectively. The chitinase activities which can hydrolyze chitin the one of components on outer layer of shrimp ranged from 14.4 unit to 171 unit. Sample E had the highest chitinase activity as 171 unit but sample B showed the lowest activity with 14.4 unit. Chitooligosaccharides of five commercial salted-fermented shrimps were consisted of monoglucosamine diglucosamine and triglucosamine.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1333-1338
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• 1998

Several enzymes of kimchi ingredients were assayed to improve the product quality using these quality related enzyme information. Among various hydrolases, amylase and protease were selected with respect to lactic acid fermentation. Peroxidase and ascorbic acid oxidase were studied for off flavor production and ascorbic acid destruction. The amount of protein in kimchi ingredients, specific and total enzyme activity of sample were compared. Regarding total enzyme activity of sample, ${\alpha}-amylase$ activity of salted and fermented anchovy, dried red pepper and salted and fermented shrimp were higher than other ingredients. Activity of salted and fermented anchovy was 2,790.0 units/g sample. Salted and fermented anchovy, oyster and Chinese radish showed the highest ${\beta}-amylase$ activity (4.4, 2.1, 1.0 units/g sample, respectively). Salted and fermented anchovy showed the highest protease activity of 13.4 PU/g sample, followed by salted and fermented shrimp and dried red pepper. For peroxidase, Chinese radish, cucumber, green onion showed the highest activity of 7.2, 6.8 and 5.6 units/g sample, respectively. In case of ascorbic acid oxidase, salted and fermented anchovy showed the strongest enzyme activity (331.4 units/g sample), followed by dried red pepper and salted and fermented shrimp.