• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.209-215
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• 1998

Trypsin-like enzyme was purified from shrimp hepatopancreas through Q-Sepharose ionic exchange, benzamidine Sepharose-6B affinity, and Superdex 75 gel chromatography. Purity of trypsin-like enzyme was increased 69-fold with $44\%$ yield. The enzyme consisted of a single polypeptide chain with a molecular weight (M.W.) of 32 kDa judged by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was completely inactivated by serine enzyme inhibitors such as soybean trypsin inhibitor (SBTI), tosyl-L­lysine chloromethyl ketone (TLCK), and leupeptin. However, the enzyme was not affected by tosyl-L-phenylalanine chloromethyl ketone (TPCK) which is a chymotrypsin specific inhibitor. The enzyme had no activity against benzoyl-tyrosine ethyl ester (BTEE) which is a chymotrypsin specific substrate. The enzyme showed high activity on the carboxyl terminal of Phe, Tyr. Glu, Arg, and Asp. However. no activity was detected against the carboxyl terminal of Pro, Trp, Cys, Gly, Val, and Ala.

• 한국패류학회지
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• 제30권1호
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• pp.41-49
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• 2014

본 연구는 카드뮴 노출에 따른 북방전복, Haliotis discus hannai의 hemolymph 및 hepatopancreas의 효소활성에 대한 변화를 관찰하였다. 북방전복은 카드뮴 0, 5, 10, 20 및 40 Cd ${\mu}g/L$의 농도에서 4 주간 노출시킨 결과, hemolymph의 phenoloxidase (PO) 활성은 40 Cd ${\mu}g/L$ 농도에서 4주 후에 유의하게 감소하였으나, alkaline phosphatase (ALP), aspartate aminotransferase (AST) 및 alanine aminotransferase (ALT) 활성은 40 Cd ${\mu}g/L$ 농도에서 4주 후에 유의한 증가를 나타냈다. 또한 hemolymph의 칼슘(Ca) 농도는 20 및 40 Cd ${\mu}g/L$의 농도에서 4주 후에 유의한 감소를 나타냈다. 한편 hepatopancreas의 superoxide dismutase (SOD) 활성은 20 및 40 Cd ${\mu}g/L$ 농도에서, catalase (CAT) 활성은 40 Cd ${\mu}g/L$ 농도에서 2주 후에 유의한 증가를 나타냈다. 따라서 카드뮴에 노출된 북방전복 hemolymph와 hepatopancreas의 효소활성은 적어도 카드뮴 농도 40 Cd ${\mu}g/L$에서 변동이 있을 것으로 예상되며, 이들 효소활성은 연안의 중금속 오염 모니터링의 기초 자료로 활용할 수 있을 것으로 생각된다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1998년도 수산관련공동학술대회발표요지집
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• pp.264.2-265
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• 1998

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1998년도 수산관련공동학술대회발표요지집
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• pp.266-267
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• 1998

• Fisheries and Aquatic Sciences
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• 제15권4호
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• pp.283-291
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• 2012

This study examines the optimal fractionation method and conditions for the isolation of endoprotease- and exopeptidase-active fractions from crude extracts of cuttlefish hepatopancreas (HP) using four fractionation methods: ammonium sulfate fractionation (ASF), polyethylene glycol fractionation (PGF), ion exchange chromatography (IEC), and gel filtration chromatography (GFC). Total endoprotease activity highest in the fraction II (concentrate of fractions 34-42; 842.60 U) of GFC, followed by fraction III (40-60% ammonium sulfate fraction; 670.25 U) of ASF, fraction I (concentrate of fractions 8-12; 436.89 U) of IEC, and fraction II (10-20% polyethylene glycol; 307.31 U) of PGF. Total exopeptidase activity of these fractions was highest in fraction II (2,704.70 U) of GFC, fraction III (2,110.50 U) of ASF, fraction III (1,605.60 U) of PGF, and fraction II (concentrate of fractions 38-44; 1,196.22 U) of IEC. These results showed that fraction II of GFC had the highest activity toward both exopeptidase and endoprotease, with exopeptidase activity being 3.21 times higher than of endoprotease. These results suggest cuttlefish HP could be used as a potential source for the extraction of exopeptidase, an enzyme capable of catalyzing the cleavage of N- and C-terminal amino acids in polypeptides, Like endoprotease, the most efficient method for separating exopeptide-active fractions was GFC.

• 한국수산과학회지
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• 제36권3호
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• pp.283-289
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• 2003

The effect on kidney, gill, and hepatopancreas of juvenile olive flounder, Paralichthys olivaceus were investigated by histological method under limit concentration of effulent of PCBs for 60 days. The free surface of epithelial cell layer in the renal tubules of kidney showed a strong positive reaction in alcian blue during all exposure period. There were also observed swelling of hemocyte in glomerulus and macrophage. At 60 days after exposure, epithelium of the renal tubules was fused and some of organism $(20\%)$ showed damage of glomerulus and eosinophlic cell in epithelium of the renal tubules. The phenomena such as the activation and increase of the chloride cell, and swelling of hemocyte in the capillary of gill were observed during all exposure period. At 60 days after exposure, swelling of the gill filament and mucous cell appeared in gill and some of organism $(30\%)$ showed swelling of the gill lamellar. Swelling of hemocyte in the capillary of hepatopancreas was observed and the free surface of epithelial layer of the bile duct showed positive reaction in alcian blue during all exposure period. Degenerated zymogen in the pancreas and swelling of the hepatocyte were occurred at 60 days after exposure.

• 한국수산과학회지
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• 제47권2호
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• pp.135-143
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• 2014

Exopeptidase active fractions from the hepatopancreas of the Argentina shortfin squid Illex argentinus, were obtained with acetone (AC 30-40%), ammonium sulfate (AS 60-70% saturation), anion exchange chromatography (AE-II, 0.2 M NaCl) and gel filtration chromatography (GF-I, 30-50 kDa) fractionation methods. A bitter peptide solution that has a bitterness equivalent to that of 2% glycylphenylalanine and prepared by tryptic hydrolysis of milk casein, was treated with the exopeptidase active fractions. The GF-I fraction was the best based on aminopeptidase activity (35.3 U/mg), percentage of recovery (30.7%) and a sensory evaluation (1.7). The amount of released amino acids increased as incubation time increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides as revealed by the reverse-phase high performance liguid chromatography profile, with three peaks (3, 5 and 6) decreasing in area (%) and three peaks (1, 2 and 4) increasing in area (%). Therefore, the GF-I fraction appeared to be ideally suited to reduce bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• 한국수산과학회지
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• 제53권1호
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• pp.112-122
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• 2020

This study investigated some enzymatic properties and bitterness improvement of an aminopeptidase retentate fraction (ARF) from common squid Todarodes pacificus hepatopancreas extract (HPE), obtained by ultrafiltration with a 10 kDa molecular weight cut off membrane. Endoprotease and aminopeptidase (AP) activity, and the purity of the ARF (>10 kDa) increased by 6.69-18.11 U/mg and 1.5-2.6 fold, respectively, compared to HPE (2.63-9.37 U/mg). The AP activity toward LeuPNA was stable at 20-55℃ and pH 5-9, but decreased slightly with increasing concentration of NaCl in the reaction mixture. The ARF was the most active MetPNA and preferentially hydrolyzed Glu, Leu and AlaPNA. The bitterness tryptic casein hydrolysates (BTCHs) were treated with ARF, and the bitterness of ARF-BTCHs significantly decreased with increasing amounts of released amino acids Ala, Val, Met, Ile and Leu, which show strong correlations with bitterness. Therefore, the ARF of T. pacificus HPE obtained by ultrafiltration may have a considerable potential for application in protein hydrolysis and appears to be ideally suited to the purpose of lowing bitterness in protein hydrolysates.

• 한국수산과학회지
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• 제54권5호
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• pp.724-732
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• 2021

This study used response surface methodology to investigate the optimal conditions to reduce the bitterness of alcalase-treated anchovy hydrolysate (AAH) by the aminopeptidase active fraction (AAF) derived from the common squid Todarodes pacificus hepatopancreas. The central composite design selected AAF/AAH ratio (X₁, %) and hydrolysis time (X₂, h) as independent variables, and the degree of hydrolysis (Y₁) and bitterness (Y₂) as dependent variables. The uncoded values of the multiple response optimization for independent variables were 3.4% for the AAF/AAH ratio and 9.2 h for the hydrolysis time. The predicted values of the yield and bitterness score of alcalase-AAF continuously treated anchovy hydrolysate (AAAH) under the optimized conditions were 68.9% and 4.6 points, respectively. Their measured values of 69.5% for yield and 4.6±0.5 points for bitterness were similar to the predicted values. The food components of AAAH were 91.4% (moisture), 7.5% (protein), 0.1% (lipid) and 0.6% (ash). The findings indicate the potential value for use as an anchovy seasoning base. The results also confirm that the bitterness of AAH was remarkably improved by AAF and implicates AAF derived from squid hepatopancreas as a good enzyme to catalyze reduced bitterness.

• 한국해양환경ㆍ에너지학회지
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• 제14권3호
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• pp.147-153
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• 2011

본 연구에서는 생산 지역이 한정되어 있고, 맛이 뛰어나 소비자들이 선호하고 있는 영덕대게와 러시아산 대게의 효율적 이용과 식품위생학적 안전성 및 먹이사슬을 통한 미량금속의 순환 연구에 기초자료를 제공하기 위하여 영덕대게(수컷, 암컷)와 러시아산 대게의 부위별 니켈, 구리, 아연, 카드뮴, 납, 비소, 크롬의 농도를 ICP-MS로 분석하였다. 인증표준물질(certified reference material, CRM)을 사용한 각 금속에 대한 회수율은 평균 81~99%로 Codex에서 요구하고 있는 수준에 부합하였다. 영덕대게의 부위별 금속 농도는 수컷과 암컷의 껍질에서는 Ni > As > Zn > Cu > Cr > Cd, 다리살은 Zn > As > Cu > Cr > Ni > Cd, 몸통살은 Zn > As > Cu > Cr > Cd > Ni, 아가미는 Cu > Zn > As > Cd > Cr > Ni 순으로 같았으며, 내장에서 수컷은 Cu > As > Zn > Cd > Ni > Cr, 암컷은 Cu > Zn > As > Cd > Cr > Ni 으로 다소 차이가 있었다. 러시아산대게는 카드뮴을 제외한 모든 금속류(니켈, 구리, 아연, 비소, 크롬)의 농도가 영덕대게와 비슷하거나 다소 낮게 나타났지만, 카드뮴 농도는 모든 부위에서 높게 나타났다. 특히, 내장에서는 약 2배, 아가미에서는 약 4배 높게 나타났다. 영덕대게의 크기별 미량금속 농도변화에서 부위별로 가장 농도가 높은 금속류(껍질의 Ni, 다리살과 몸통살의 Zn, 내장과 아가미의 Cu)들은 전반적으로 성장할수록 감소하는 경향이 있는 반면, 내장에 가장 많이 축적되어 있는 카드뮴의 농도는 전반적으로 증가하는 경향이 있으며, 성장과 더불어 내장 내 생물축적현상이 가중될 가능성이 있다.