• Proceedings of the Korean Nutrition Society Conference
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• 2002.05a
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• pp.156-156
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• 2002

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.577-583
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• 2001

The digestive enzyme activities such as $\alpha-amylase$, trypsin and pepsin from the laboratory-reared river puffer Takifugu obscurus were measured from the time course of 1 day until the 65 day after hatching. In the case of $\alpha-amylase$, it was showed minimum activity of 0.0493 U/mg at the total length (TL) 10 mm, and showed maximum activity of 0.1480 U/mg at 19 mmTL. Trypsin and pepsin were showed their maximum activities of 0.0264, 0.0258 U/mg and 0.0178, 0.0201 U/mg when the total length of 16 and 24 mm, and represented remarkable correlations between the changes of enzyme activity and growth rate. The ontogenetic variations of digestive enzymes were represented clearly different patterns; i.e, the pepsin showed higher activity when the periods of larva ($4\~5\;mmTL$) and juvenile II ($19\~24\;mmTL$), however, the trypsin represented maximum activity at the stages of juvenile I ($11\~16\;mmTL$) and young fish (27 mmTL), respectively.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.49-58
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• 2006

This study was conducted to evaluate effects of mud flat bacteria origin protease supplementation on growth performance, amino acid digestibility, blood characteristics, meat quality, fecal VFA (volatile fatty acids) and NH3-N (ammonia nitrogen) concentration in finishing pigs. Eighty pigs (Landrace×Yorkshire×Duroc, 60.08±2.69 kg average initial body weight) were used during experimental period. Dietary treatments included 1) high nutrient density diet, 2) high nutrient density diet+0.1% protease, 3) low nutrient density diet and 4) low nutrient density diet+0.1% protease. For overall period, ADG was improved in treatment of high nutrient density diet added protease compared with treatment of low nutrient density diet without protease (P<0.05). DM and N digestibilities were improved in treatments of high nutrient density diet and low nutrient density diet added protease compared with treatment of low nutrient density diet without protease (P<0.05). Essential amino acid digestibility was improved in treatment of low nutrient density diet added protease compared with other treatments (P<0.05). Nonessential amino acid digestibility was improved in treatment of high nutrient density diet added protease compared with treatments of high and low nutrient density diet (P<0.05). BUN (blood urea nitrogen)　concentration in blood was increased in treatment of high nutrient density diet added protease compared with treatment of low nutrient density diet without protease (P<0.05). L*value of M. longissimus dorsi muscle was increased in treatments of low nutrient density diet compared with treatments of high nutrient density diet (P<0.05). In conclusion, mud flat bacteria origin protease was effective for improving growth performance, amino acid digestibility and influencing BUN concentration and meat color in finishing pigs.

• Journal of Animal Science and Technology
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• v.51 no.1
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• pp.39-44
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• 2009

The objective of this study was to investigate the effects of an enriched diet supplemented with aqueous fibrolytic enzyme products (FEP) on In vitro fermentation and growth performance of Hanwoo Steers. Total mixed ration combined with fibrolytic enzyme products showed a slight increase in the pH level on In vitro fermentation. Acetate ratio in volatile fatty acids, and the concentration of total volatile fatty acids were significantly greater at 12hr and 24hr after cultivation (p<0.05). Dry matter digestibility was significantly increased in groups supplied with aqueous fibrolytic enzyme products at 24hr after cultivation (p<0.05). In a rearing trial, the average daily gain and feed efficiency improved in the treatment groups supplied with aqueous fibrolytic enzyme products. Nutrient digestibility such as DM, crude fiber, NDF, and ADF digestibility were also significantly increased with the addition of aqueous fibrolytic enzyme products (p<0.05). Therefore, the aqueous fibrolytic enzyme products supplementation on In vitro fermentation is effective in improving the condition of rumainal fermantation. Also two kinds of aqueous fibrolytic enzyme products were found to be effective in improving the average daily gain and feed efficiency in Hanwoo Steers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.875-881
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• 1998

To develop functional food material with angiotensin converting enzyme (ACE) inhibitory peptides, muscle protein of anchovy, Engraulis japonica was hydrolyzed during 48 hrs by digestive pretenses such as pepsin, trypsin, $\alpha$-chymotrypsin, and commercial proteases such as papain, bromelain, complex enzyme, Elavourzyme, Novozym, Neutrase, Protamex and Alcalase. The only $50\%$ ethanol soluble hydrolysates were tested for inhibitory activity against ACE and yield of $50\%$ ethanol soluble peptide-nitrogen ($ESPN_{50}$). ACE inhibition effects and yield of $ESPN_{50}$ occurred as hydrolysis time increased to 8 hrs, Among those pretenses tested, hydrolysates by Alcalase and $\alpha$-chymohypsin had greater ACE inhibitory activity (80 and $74\%$, reipectively) with eletated levels of $ESPN_{50}$ (48 and 58 mg/ml, respectively), while Protamex hydrolysates had greater ACE inhibitory activities ($73\%$) with reduced levels of $ESPN_{50}$ (7.2mg/ml) than others. Amino acid compositions of $50\%$ ethanol solubles obtained from those hydrolysates were rich in glutamic acid, aspartic acid, cysteine and leucine.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.276-280
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• 2011

This study investigated the activation conditions of pancreatic enzymes from porcine pancreas. Duodenum induced the activation of pancreatic protease and lipase in pancreas. When 10% duodenum was added to pancreatic juice and the mixture was incubated at $30^{\circ}C$ for 90 min or at $25^{\circ}C$ for 4 hrs, the activities of pancreatic protese and lipase reached the peak. When the pancreatin was prepared by sequential process of enzymatic activation at $25^{\circ}C$ for 4 hrs, centrifugation, acetone precipitation and freeze-drying, the specific activities of pancreatic protease, lipase and amylase were 136, 116 and 400 U/mg-protein, respectively. The protease, lipase and amylase activities of the prepared pancreatin were 5.4, 58.0 and 16.0 times higher than those of USP standard, respectively.

• Journal of Aquaculture
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• v.18 no.4
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• pp.245-251
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• 2005

This study was investigated the condition of their maximum activity to assay the enzymes of rotifer, Brachionus rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin and TG-lipase activities of rotifer were higher and more sensitive in phosphate-NaOH buffer than Tris-HCl buffer. $\alpha$-amylase, trypsin and TG-lipase activities were appeared the maximum at pH 8.0, and total alkaline protease activity showed the maximum activity at pH 7.0. $\alpha$-amylase activity showed the highest activity at $40^{\circ}C$, and total alkaline protease and trypsin activities were assayed the highest at $55{\~}60^{\circ}C$. However, TG-lipase activity was appeared the highest at $25{\~}30^{\circ}C$. The optimum substrate concentration of enzyme activity of a-amylase, total alkaline protease, rypsin and TG-lipase were $3.5\%$ starch, $\0.6%$ azo-casein, $87.5{\mu}M$ BApNA and 81.2 mM olive oil, respectively. The optimum reaction time of enzyme activity of $\alpha$-amylase, total alkaline protease, trypsin and TG-lipase were increased up to 40, 60, 30 and 25 min., respectively. The data obtained in this study could be used for the digestive enzyme research of rotifer, B. rotundiformis.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.219-232
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• 1989

The present study was done to investigate the mechanism of Pancreatic digestive enzyme secretion in response to dietary components in chicks. A simplefied pancreatic juice collection method, useful for a short-term experiment, was developed. By wing vein injection, it was shown that the increased trypsinogen and chymotrypsinogen, while neither other single amino acids nor glucose affected the secretion of enzymes, amylase, trypsinogen and chymotrypsinogen. Cholecystokinin (CCK) had an immediate effect on pancreatic enzyme secretion and this response was in a dose dependent fashion. The injection of CCK seemed to have selective stimulation favoring the secretion of chymotrypsinosen followed by amylase and trypsinogen. Simultaneous injection of single amino acid with CCK increased digestive enzyme secretion to various extents depending on the kind of amino acids whereas the injection of glucose with CCK did not affect when compared with that of CCK'alone. By varying doses, synergetic action of CCK plus amino acid on the secretion of pancreatic digestive enzymes was observed at 0.5mM for Val and 5mM for Arg. A further attempt was made to examine the effect of combined administration of amino acids with CCK on pancreatic enzyme secretion. The injected substances were an AAs mixture and combination of selected amino acids, i.e. Thr＋Phe＋Ile, Thr＋Phe. Thr＋Ile or Phe＋Ile. When increases in enzyme outputs for the first 30 min were compared , it was shown that the responses of three enzymes, amylase, trypsinogen and chymotrypsinogen, brought about by the administration of the AAs mixture was almost entirely accounted for by the combined injection of Thr＋Phe. Thus, it was well demonstrated that CCK and amino acids had a synergetic action on the secretion of a specific pancreatic digestive enzyme depending on a kind of amino acid injected.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.238-244
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• 2009

Food allergy is a serious nutritional problem in both children and adults. Therefore, food allergenicity reduction methods are greatly needed. The allergenicity is altered by various manufacturing processes, and the digestibility of food proteins can be affected by food processing. This study was conducted to investigate the effect of in-vitro digestibility on the allergenicity of autoclaved market pork sausages using pepsin (30min) and trypsin (5, 30, 60, 90, and 120min). The binding ability of the porcine serum albumin (PSA) from sausages A and B significantly decreased by about 30 and 23%, respectively, after autoclave treatment (121; 5, 10, and 30 min). After the pepsin and trypsin treatments, the binding ability of products A and B at 30 min decreased. These competitive indirect enzyme-linked immunosorbent assay (ci-ELISA) results corresponded well with the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting results. The results demonstrated that the allergenicity of pork sausages considerably decreased after autoclave treatment, and were also maintained or decreased after enzyme treatment. Accordingly, autoclave treatment represents a promising processing technology for the reduction of the allergenicity of diverse food products.

• Journal of Life Science
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• v.19 no.9
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• pp.1226-1231
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• 2009

Enzyme substitution with recombinant phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is currently being explored for treatment of phenylketonuria (PKU), an autosomal recessive genetic disorder with mutations of the gene encoding phenylalanine-4-hydroxylase (EC 1.14.16.1). However, oral administration of PAL is limited because of proteolytic digestion in the gastrointestinal tract. The aim of this study was to determine the biochemical properties of PAL and delinate the susceptibility of wild-type PAL to pancreatic proteolysis by exploring several mutants, and to develop therapeutic drugs with PAL for PKU. The specific activity of PAL was assayed and its optimal pH, temperature stability, and intestinal protease susceptibility were investigated. Its $V_{max}$ values for phenylalanine and tyrosine were 1.77 and $0.47{\mu}mol$/ min/mg protein, respectively, and its $K_m$ values were $4.77{\times}10^{-4}$ and $4.37{\times}10^{-4}\;M$, respectively. PAL showed an optimal pH at 8.5, corresponding to the average pH range of the small intestine. It showed no loss of activity at $-80^{\circ}C$ for 5 months and possessed 93.4% of its activity under $4^{\circ}C$ for 4 wks. PAL was susceptible to chymotrypsin digestion and, to a lesser extent, to trypsin, elastase, carboxypeptidase A, and B. The trypsin and chymotrypsin cleaving sites were mutated to investigate protection from pancreatic digestion and the specific activities of these mutants were evaluated. The six mutants displayed low specific activities compared to the wild-type, suggesting that the primary trypsin and chymotrypsin cleaving sites may be essential for catalytic reaction. The PAL mutants could therefore be applied as a pretreatment modality without susceptibility to proteolytic attack, however, additional modification for enhancing enzymatic activity is needed to reduce the Phe levels effectively.