• Food Science of Animal Resources
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• v.37 no.5
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• pp.682-689
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• 2017

The aim of this study was to investigate the digestibility of different Korean Hanwoo beef cuts using an in vitro digestion model, in vitro physicochemical upper gastrointestinal system (IPUGS). The four most commonly consumed cuts - tenderloin, sirloin, brisket and flank, and bottom round - were chosen for this study. Beef samples (75 g) were cooked and ingested into IPUGS, which was composed of mouth, esophagus, and stomach, thereby simulating the digestion conditions of humans. Digested samples were collected every 15 min for 4 h of simulation and their pH monitored. Samples were visualized under a scanning electron microscope (SEM) to examine changes in the smoothness of the surface after digestion. Analysis of the amino acid composition and molecular weight (MW) of peptides was performed using reverse-phase high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively. Following proteolysis by the gastric pepsin, beef proteins were digested into peptides. The amount of peptides with higher MW decreased over the course of digestion. SEM results revealed that the surface of the digested samples became visibly smoother. Total indispensable and dispensable amino acids were the highest for the bottom round cut prior to digestion simulation. However, the total amount of indispensable amino acids were maximum for the tenderloin cut after digestion. These results may provide guidelines for the elderly population to choose easily digestible meat cuts and products to improve their nutritional and health status.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.291-301
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• 2018

To shorten the production cycle of Zaodan, this study first pickled Zaodan by a novel technology - vacuum decompression technology. Vacuum decompression technology could reduce the pickling time of Zaodan from 20 wk to about 9 wk. The protein content, moisture and pH of the Zaodan egg white gradually decreased with a concomitant increase in salt during the pickling process. The total sulfhydryl group (SH) group content of the egg white proteins was increased to $2.43{\times}10^{-3}mol/L$ after being pickled for 30 d, whereas the content of disulphide bonds (SS) was reduced to $23.35{\times}10^{-3}mol/L$. The surface hydrophobicity was lowest after pickling for 30 d. In addition, great changes occurred in the secondary structure of the egg white proteins after pickling for 20 d. The disappearance of ovomucin was noticeable based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.

• Journal of Pharmacopuncture
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• v.16 no.2
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• pp.46-54
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• 2013

Objective: This study was undertaken to isolate a fibrin(ogen)olytic enzyme from the snake venom of Gloydius blomhoffii siniticus and to investigate the enzymatic characteristics and hemorrhagic activity of the isolated enzyme as a potential pharmacopuncture agent. Methods: The fibrinolytic enzyme was isolated by using chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fibrin plate assay. The characteristics of the enzyme were determined by using fibrin plate assay, protein hydrolysis analysis, and hemorrhage assay. Its amino acid composition was determined. Results: The fibrin(ogen)olytic enzyme with the molecular weight of 27 kDa (FE-27kDa) isolated from G. b. siniticus venom consisted of two heterogenous disulfide bond-linked polypeptides with the molecular weights of 15 kDa and 18 kDa. When more than $20{\mu}g$ of FE-27kDa was applied on the fibrin plate, fibrinolysis zone was formed as indicating its fibrinolytic activity. The fibrinolytic activity was inhibited completely by phenylmethanesulfonylfluoride (PMSF) and ethylenediaminetetraacetic acid (EDTA) and partially by thiothreitol and cysteine. Metal ions such as $Hg^{2+}$ and $Fe^{2+}$ inhibited the fibrinolytic activity completely, but $Mn^{2+}$ did not. FE-27kDa preferentially hydrolyzed ${\alpha}$-chain of fibrinogen and slowly hydrolyzed ${\beta}$-chain, but did not hydrolyze ${\gamma}$-chain. High-molecular-weight polypeptides of gelatin were hydrolyzed partially into polypeptides with molecular weights of more than 45 kDa. A dosage of more than $10{\mu}g$ of FE-27kDa per mouse was required to induce hemorrhage beneath the skin. Conclusion: FE-27kDa was a serine proteinase consisting of two heterogeneous polypeptides, hydrolyzed fibrin, fibrinogen, and gelatin, and caused hemorrhage beneath the skin of mouse. This study suggests that the potential of FE-27kDa as pharmacopuncture agent should be limited due to low fibrinolytic activity and a possible side effect of hemorrhage.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.414-421
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• 2011

Purpose: Recently, an increase in the number of patients sensitized to rice allergen with or without clinical symptoms has been reported. This study was designed to determine the major allergens in rice and their clinical significance. Methods: Twenty-four children (15 boys and 9 girls; mean age, 16.3 months) with allergic disease, who were sensitized to rice antigen (by UniCAP) in the Pediatric Allergy Respiratory Center at Soonchunhyang University Hospital, were enrolled in this study. The allergenicity of various types of rice (raw, cooked, and heat-treated, simulated gastric fluid [SGF], and simulated intestinal fluid [SIF]) was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoglobulin E (IgE) immunoblots. The patients' medical records, including laboratory data and allergy symptoms after ingestion of rice were reviewed. Results: Patients were sensitized to an average of 13.5 food antigens and their mean total IgE was 6,888.7 kU/L. In SDS-PAGE, more than 16 protein bands were observed in the raw rice, whereas only 14-16 kDa and 31-35 kDa protein bands were observed in cooked rice. The common SDS-PAGE protein bands observed in SGF-, SIF-, and heat-treated rice were 9, 14, and 31 kDa. In a heated-rice IgE immunoblot, protein bands of 9, 14, and 31-33 kDa were found in 27.8%, 38.9%, and 38.9% of all sera, respectively, and in 50%, 50%, and 75%, of ser a from the 4 symptomatic patients, respectively. Conclusion: The 9-, 14-, and 31-kDa protein bands appeared to be the major allergens responsible for rice allergy symptoms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.100-105
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• 2001

One-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE) was used to determine whether it would provide improved resolving power of hordein proteins concomitant with improved identification of Korean barley cultivars and germplams. This system gave rapid and reproducible separations of hordein polypeptides. Total fourteen of clear and easily scorable subunits were identified in Korean barley cultivars and germplasms and their polymorphic constitutions could provide biochemical genetic information in progeny analysis and endosperm quality improvement in barley breeding programs. Each hordein polypeptides residing in B, C, and D hordein pattern designations were scored to prepare a cultivar catalogue of protein patterns. On the basis of this character, 7 hordein polypeptide patterns were constructed from 108 barley cultivars and experimental lines. The molecular weight of hordein subunits in Korean barley cultivars and experimental lines varied in the range of 98 to 48 kDa. In contrast, less polymorphic hordein polypeptides were found in the low protein barley lines including malting barleys than those found in Korean barley cultivars and experimental lines.

• Applied Biological Chemistry
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• v.36 no.2
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• pp.121-126
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• 1993

To extract insoluble proteins of sesame meal residue by using microorganism, the sesame meal residue was treated with crude enzyme solution from Bacillus sp. CW-1121. It was found that the solubility reached to maximum at pH 7.5, $45^{\circ}C$. Under optimum condition, the nitrogen solubility with the enzyme solution from Bacillus sp. CW-1121 reached to 60% in 2 hours. Nitrogen solubility of protein from sesame meal showed minimum value at pH 4.5 and significantly increased above pH 6.0. When the protein from sesame meal extracted with Bacillus sp. CW-1121 was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, water soluble protein was showed 4 bands and salt soluble protein was showed 2 bands. The amino acid composition of water soluble protein, salt soluble protein and free amino acid indicated relatively high contents of serine (17.24 mg/g), glutamic acid (10.77 mg/g) and glutamic acid (6.55 mg/g). Specially, the contents of essential amino acids were high.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.129-136
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• 2007

This study was performed to determine the protein profiles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Angiotensin-I-converting enzyme(ACE) inhibitory activity (IC50) as affected by the various meat cuts, digestion times with pepsin. Hydrolysates having the protein concentration of 10 ug/mL had approximately 36∼39% ACE inhibitory activities, regardless of meat cut and digestion time. Protein concentration and ACE inhibitory activity of the diluted hydrolysate increased after 1-hr digestion. In original hydrolysates, ACE inhibitory activities of loin had higher than those of round (P<0.05). In addition, non-heated hydrolysates had higher ACE inhibitory activities than heated counterparts. When myosin B was digested by pepsin more than 1 hr, improved ACE inhibitory activities were observed as compared to the non-digested control.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.317-325
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• 2001

For heuristic purposes, the relative ratio of urease contents inside and outside cells was surveyed using nine ureB+ strains of Helicobacter pylori. the ratio of the enzyme specific activity appeared to vary greatly between the various H. pylori strains, ranging from 0.5 to 2.5. Besides the above compartment, urease was also richly found in the membrane fraction, especially in either peripheral or integral form. The urease distribution across the H. pylori membrane was significantly influenced by the ambient pH; the specific activity of external urease was highest at pH 5.5 with a narrow plateau, whereas the internal specific activity was highest within a pH range of 4.5 to 6.5 with a broad plateau. These finding strongly suggest that H. pylori urease is secretory and responded to the external pH. However, at pH 4.0 or below, no urease activity was detected in either the internal or external compartment, although an increase in the color development with 2,4,6-trinitrobenzene sulfonate (TNBS) was observed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these phenomena may be related to a specific proteolysis in certain proteins, including urease or ${\gamma}$-glutamyl transpeptidase. Interestingly, the effect of ammonium ions n alleviating the enzyme inactivation inside the H. pylori cells was remarkably similar to that of D-glucose. In addition, it would appear that the cation acted as a surrogate of not only $Na^+$ but also $K^+$ thereby increasing the H. pylori P-type ATPase activity. This is of great interest, as it implies that the urease action in H. pylori is indispensible at any locus.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.119-124
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• 2003

This study was conducted to evaluate the practical usefulness of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PACE) fingerprinting of whole cell proteins far the identification of lactic acid bacteria in Kimchi. SDS- PACE of whole cell proteins of the reference strains and lactic acid bacteria isolated from Kimchi yielded differential banding patterns that were highly specific fingerprints, thus making it possible to identify. Identification of the isolates from Kimchi was achieved by comparing the SDS-PAGE fingerprints of isolates to those of reference strains. In addition, the reliability of SDS-PAGE was examined by comparing the results with those of the APL 50 CHL system assay and 16S rRNA gene sequence. SDS-PACE assay showed a different identity to reference strains, while the APL 50 CHL system and 16S rRNA gene sequence could not distinguish a few strains. Therefore, SDS-PAGE of the whole cell proteins is a specific and a reliable method that will be useful for the identification of lactic acid bacteria in Kimchi to the species level, and can be used as an alternative or complementary identification method.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1096-1104
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• 2014

$\small{L}$-Asparaginase from gram-positive bacteria has been poorly explored. We conducted recombinant overexpression and purification of $\small{L}$-asparaginase from Staphylococcus sp. OJ82 (SoAsn) isolated from Korean fermented seafood to evaluate its biotechnological potential as an antileukemic agent. SoAsn was expressed in Escherichia coli BL21 (DE3) with an estimated molecular mass of 37.5 kDa, determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Consistent with asparaginases in gram-negative bacteria, size-exclusion chromatography determined SoAsn as a homodimer. Interestingly, the optimal temperature of SoAsn was $37^{\circ}C$ and over 90% of activity was retained between $37^{\circ}C$ and $50^{\circ}C$, and its thermal stability range was narrower than that of commercial E. coli $\small{L}$-asparaginase (EcAsn). Both SoAsn and EcAsn were active between pH 9 and 10, although their overall pH-dependent enzyme activities were slightly different. The $K_m$ value of SoAsn was 2.2 mM, which is higher than that of EcAsn. Among eight metals tested for enzyme activity, cobalt and magnesium greatly enhanced the SoAsn and EcAsn activity, respectively. Interestingly, SoAsn retained more than 60% of its activity under 2 M NaCl condition, but the activity of EcAsn was reduced to 48%. Overall, the biochemical characteristics of SoAsn were similar to those of EcAsn, but its kinetics, cofactor requirements, and NaCl tolerance differed from those of EcAsn.