• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.348-348
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• 2006

In the present study, porcine pepsin in various pH conditions was investigated by small-angle X-ray scattering (SAXS) in order to detailed information on the structure and its variations with pH conditions. These analyses identified the structure of pepsin, and compared with that obtained by single crystallography. Moreover, this study found the structure' variations with changing pH conditions. All the results will be discussed with considering the conformational characteristics of pepsin in solution and further correlate to the biological and spectroscopic characteristics reported previously.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.151-157
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• 2014

This study investigated the effects of three proteases (trypsin, pepsin and chymotrypsin) on the hydrolysis efficiency of porcine placenta and the molecular weight (Mw) distributions of the placental hydrolysates. Because placenta was made up of insoluble collagen, the placenta was gelatinized by applying thermal treatment at $90^{\circ}C$ for 1 h and used as the sample. The placental hydrolyzing activities of the enzymes at varying concentrations and incubation times were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel permeation chromatography (GPC). Based on the SDS-PAGE, the best placental hydrolysis efficiency was observed in trypsin treatments where all peptide bands disappeared after 1 h of incubation as compared to 6 h of chymotrypsin. Pepsin hardly hydrolyzed the placenta as compared to the other two enzymes. The Mw distribution revealed that the trypsin produced placental peptides with Mw of 106 and 500 Da. Peptides produced by chymotrypsin exhibited broad ranges of Mw distribution (1-20 kDa), while the pepsin treatment showed Mw greater than 7 kDa. For comparisons of pre-treatments, the subcritical water processing (37.5 MPa and $200^{\circ}C$) of raw placenta improved the efficiency of tryptic digestions to a greater level than that of a preheating treatment ($90^{\circ}C$ for 1 h). Consequently, subcritical water processing followed by enzymatic digestions has the potential of an advanced collagen hydrolysis technique.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.741-746
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• 2005

To investigate the basic information and the possibility of ACE-inhibitory peptides for antihypertension materials, goat's caisin (CN) was hydrolyzed by various proteolytic enzymes and ACE-inhibitory peptides were separated and purified. ACE-inhibition ratios of enzymatic hydrolysates of goat's CN and various characteristics of ACE-inhibitory peptides were determined. ACE-inhibition ratios of goat's CN hydrolysates were shown the highest with 87.84% by pepsin for 48 h. By Sephadex G-25 gel chromatograms, Fraction 3 from goat's CN hydrolysates by pepsin for 48 h was confirmed the highest ACE-inhibition activity. Fraction 3 g and Fraction 3 gh from peptic hydrolysates by RP-HPLC to first and second purification were the highest in ACE-inhibition activity, respectively. The most abundant amino acid was leucine (18.83%) in Fraction 3 gh of ACE-inhibitory peptides after second purification. Amino acid sequence analysis of Fraction 3 gh of ACE-inhibitory peptides was shown that the Ala-Tyr-Phe-Tyr, Pro-Tyr-Tyr and Tyr-Leu. IC$_{50}$ calibrated in peptic hydrolysates at 48 h, Fraction 3, Fraction 3 g and Fraction 3 gh from goat's CN hydrolysates by pepsin for 48 h were 29.89, 3.07, 1.85 and 0.87 g/ml, respectively. Based on the results of this experiment, goat's CN hydrolysates by pepsin were shown to have ACE-inhibitory activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.445-453
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• 2016

Seahorse Hippocampus abdominalis a marine teleost fish, has long been used as one of the essential materials in traditional Chinese medicine. However, the uses of seahorse have been limited due to its high cost, despite its beneficial biological activities. Seahorse has not been widely explored for its biofunctional properties and active components. In the present study, the enzymatic hydrolysates of seahorse were prepared by using two digestive enzymes (trypsin and pepsin) and five food grade enzymes (neutrase, protamex, alcalase, kojizyme, and flavourzyme). The enzymatic hydrolysates indicated higher hydrolysis yields than its water extract. Among them, the distilled water-pepsin hydrolysate (DP) which was obtained by distilled water extraction followed by pepsin hydrolysis, showed the highest yield and protein content as well as the highest alkyl radical scavenging activity. Also, it provided protective effects against oxidative stress induced by AAPH in vero cell and zebrafish. Further fractionation based on the molecular weight was carried out to identify it’s active components, and < 5 kDa (less than 5 kDa) molecular weight fraction was confirmed to have the highest antioxidant activity. In conclusion, this study suggests that DP of seahorse has antioxidant properties, and might be a novel and useful material from the marine origin for healthy functional foods and cosmetics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.970-975
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• 2010

Because Lonicerae Flos has effects of antiinflammatory and antioxidant, we studied an effect of Lonicerae Flos on reflux esophagitis (RE) through those effects. Rats were treated with three different dosages of LF (500, 250 and 125 mg/kg) orally for 14 days before pylorus and forestomach ligation. Six hrs after pylorus and forestomach ligation, we dissected a stomach and examined a stomach volume, gastric acid output, pepsin release in the stomach, total hexose, sialic acid in stomach tissue and histamine contents of sera. The results were compared with an ${\alpha}$-tocopherol (once orally, 1hr before operation, 30 mg/kg) treated group in which the effects on RE were already confirmed. Lonicerae Flos extract (LE) reduced gastric volumes compared to RE control. This indicate that LE protect a stomach mucosa by depressing of gastric acid release and corresponse with a reducing histamine content of serum. And LE decreasd a volume of pepsin in stomach compraed to RE control, LE increased contents of total hexose and sialic acid based on esophageal and gastric mucus. This indicated that an increased mucus by LE protected inflammation of esophagus mucosa and gastric mucosa induced by gastric acid. So, LE suppressed a gasric acid by decreasing a pepsin release in stomach, suppressed an injury of esophagus inducted by gastric acid with increasing esophageal mucus and a minimum dose of LE to RE was 250 mg/kg. The results suggest that antioxidant effects of LF could attenuate the severity of reflux esophagitis and prevent the esophageal mucosal damage, and validate its therapeutic use in esophageal reflux disease.

• Korean journal of food and cookery science
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• v.13 no.2
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• pp.168-172
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• 1997

Yolk immunoglobulins (yIgG) from hen's egg were purified. To investigate the stability of yIgG to digestive enzymes, the changes of antigen binding activities (ABC) after in vitro proteolysis were examined by competitive ELISA. After 30 min exposure to pepsin, the ABC of yIgG was lost. However, comparing with native yIgG, the ABC of pepsin digested yIgG was decreased, but considerable amount of ABC was remained after 30 min exposure to pepsin in 50% saccharose solution. Therefore, the stability of yIgG to pepsin digestion was improved by the addition of saccharose to yIgG solution. The ABC of yIgG was considerably remained after exposure to trypsin and chymotrypsin for 8 hr. YIgG showed especially good stability to chymotrypsin proteolysis.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1316-1318
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• 1997

The isolated ${\kappa}-Casein$ on gel permeation chromatography was hydrolyzed by chymosin, trypsin, and pepsin. The 3% TCA soluble portion of the hydrolysates were dialyzed on the angiotensin-I converting enzyme (ACE) inhibition rate (%,) and inhibitory activity $(IC_{50})$ were determined. The trypsin hydrolysate exhibited the highest ACE inhibition rate while the chymosin hydrolysation showed the lowest activity. The hydrolysate was dialyzed using dialysis membrane with various molecular cut-offs, and $IC_{50}$ was determined. As the pore size of the dialysis tubing increased, the ACE inhibitory activity decreased.

• Journal of Animal Science and Technology
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• v.47 no.1
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• pp.83-90
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• 2005

ACE-inhibitory peptides derived from goat's whey hydrolyzed by various proteolytic enzymes were separated and purified for antihypertension materials. The highest ACE-inhibitory activity of goat's whey hydrolysates was 85.5 % by pepsin for 72 hrs. Also the highest ACE-inhibitory activity of goat's whey hydrolysates was F-4 by pepsin for 72 hrs by Sephadex G-25 gel chromatograms. F-4e and F-4ed from F-4 by RP-HPLC to first and second purification were the highest in ACE-inhibitory activity, respectively. The most abundant amino acid was leucine(I 8.54 %) in F-4ed of ACE-inhibitory peptides after second purification. Amino acid sequence of F-4ed of ACE-inhibitory peptides showed Leu-Lys-Asp-Tyr-Gly-GlyVal- Ser-Leu and Leu-Gly-Asp-Gly-Ala-Gly- Asp-Val-Ala-Phe. $IC_{50}$ calibrated in peptic hydrolysates(72 hrs), F-4, F-4e and F-4ed from goat's whey hydrolysates by pepsin for 72 hrs were 33.93, 28.75, 11.74 and 1.09 mg/ml, respectively. From the results of this experiment, goat's whey hydrolysate by pepsin was shown to have ACE-inhibitory activity.

• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.149-154
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• 2014

It is already known that adzuki beans (Vigna angularis) are able to control appetite. Therefore, this study tested the proteins isolated from adzuki beans for their protease resistance and interaction with the intestinal mucosa. The major proteins from adzuki beans were found to be resistant to the digestive enzymes pepsin and pancreatin, and were identified using 2D-SDS-polyacrylamide gel electrophoresis and mass spectrometry. The major adzuki proteins were easily fractionated by treating the soluble protein extract with 10mM $CaCl_2$, and were found to contain lactotransferrin, a homologous protein to the dynein light chain domain, proteinase inhibitor, and proteins with unknown functions. From a tissue binding assay using mouse intestinal tissue sections, the major protein fraction showed weak, yet significant and specific binding to the mucosa layer of the small intestine. Thus, the current results suggest that adzuki proteins are resistant to digestive enzymes, which enables them to survive protease digestion in the intestinal tract, plus they may interact with the intestinal mucosa layer. Therefore, the molecules responsible for controlling appetite in adzuki beans are presumably protease-resistant proteins that interact with the intestinal mucosa or delay digestion in the digestive tract.

• Food Science and Preservation
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• v.16 no.3
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• pp.419-426
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• 2009

The antioxidant and antimicrobial effects of acid-soluble and pepsin-solubilizable shark (Isurus oxyrinchus) collagens (SC) (ASSC: acid-soluble shark skin collagen, ASMC: acid-soluble shark meat collagen, PSSC: pepsin-solubilizable shark skin collagen, PSMC: pepsin-solubilizable shark meat collagen) and standard marine collagen (STMC) as materials, and the ability of these materials to inhibit tyrosinase and elastase, were investigated. The electron-donating ability of SC ($1{\sim}5\;g/mL$) was $14.91{\sim}17.21%$, which was $3.0{\sim}3.6$-fold higher than that of STMC at the same concentration. Also, the SOD(superoxide dismutase)-like activity of SC (5.80 mg/mL) was $4.67{\sim}37.28%$, thus $3.0{\sim}3.6$-fold greater than that of STMC. The MIC values of SC against Staphylococcus aureus and Salmonella enteritidis were $5{\mu}g$/disc, which were remarkably lower than that of STMC ($200{\mu}g$/disc). There was no antimicrobial activity against Escherichia coli in STMC, but the MIC against E. coli was $200{\mu}g$/disc for acid-soluble SC and $100{\mu}g$/disc for pepsin-solubilizable SC. The inhibition of tyrosinase by SC (3-5 mg/mL) was $58.95{\sim}98.16%$, $3.34{\sim}3.74$-fold higher than that of STMC ($17.67{\sim}26.25%$). Also, elastase inhibition by SC (at 1 mg/mL) was $53.33{\sim}80.0%$, $1.1{\sim}4.0$-fold greater than that of STMC. These results indicated that shark collagens may be valuable new functional materials owing to their antioxidant and antimicrobial properties, and because the inhibitory activities against elastase and tyrosinase are better than those of standard marine collagen.