• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.133-142
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• 1998

Effects of protein heat treatment and surfactant additionoo the orthokindetic stability of $\beta$-lactoglobulin-stabilized emulsions have been investigated under turbulent flow conditions. In studies on protein-stabilized emulsions, samples which had been subjected to heat treatment(i.e. the protein solution orthe emulsion) have been found to be more prone to orthokinetic coalescene than the untreated ones. The emulsions stabilized with protein heated above the denaturation temperature(i.e. 7$0^{\circ}C$) showed the bigger initial average droplet size, which resulted in an increased orthokinetic coalescenece rate. The storage of the protein-stabilized emulsion at high temperature prior to the shearing experiment also made the emulsion less stable in the shear field. Interestingly. the addition of DATEM has been found to produce a substantial increase in orthokinetic stability of the heat-denatured protein-stabilized emulsion system, although Tween 20 is the opposite case.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.989-1001
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• 2023

Processed foods containing pork fat tissue to improve flavor and gain economic benefit may cause severe issues for Muslims, Jews, and vegetarians. This study aimed to develop an indirect enzyme-linked immunosorbent assay (iELISA) based on a monoclonal antibody specific to thermal stable-soluble protein in pork fat tissue and apply it to detect pork fat tissue in heat-processed (autoclave, steam, roast, and fry) beef meatballs. To develop a sensitive iELISA, the optimal sample pre-cooking time, coating conditions, primary and secondary dilution time, and various buffer systems were tested. The change in the iELISA sensitivity with different 96-well microtiter microplates was confirmed. The detection limit of iELISA performed with an appropriate microplate was 0.015% (w/w) pork fat in raw and heat-treated beef. No cross-reactions to other meats or fats were shown. These results mean that the iELISA can be used as an analytical method to detect trace amounts of pork fat mixed in beef.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.728-735
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• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.822-827
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• 2000

Gamma irradiation was applied to reduce shrimp allergy. Shrimp heat-stable protein(HSP) and shrimp protein extract were gamma-irradiated at 1, 3, 5, 7 or 10 kGy in an aqueous state (1.0 mg/mL). The changes in allergenic and antigenic properties of protein extract and HSP resulted from gamma irradiation were monitored by ELISA with mouse mAb or human patients sera and immunoblotting. Conformational changes in irradiated HSP were measured by both GPC-HPLC and SDS-PAGE. The binding ability of shrimp allergic patients IgE to irradiated protein extract or irradiated heat-stable protein was dose-dependently reduced. When measured by gel permeation chromatography and sandwich ELISA, the amount of intact heat-stable protein in the irradiated solution was reduced by gamma irradiation depending upon the applied dose. SDS-PAGE showed that the main band disappeared and new bands appeared in a higher molecular weight zone. The results provide a new possibility to use irradiation process for reducing the allergenicity of shrimp.

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.39-39
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• 1997

Native strain of inhibitory SERPINS (Serine protease inhibitors) is thought to be used in the facile conformational switch to play biological regulation. Many heat stable variants of $\alpha$$_1$-antitrypsin, a prototype of inhibitory serpins, increased their stability by reducing the native strain.(omitted)

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1118-1122
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• 2014

The present study shows that DR1114 (Hsp20), a small heat shock protein of the radiation-resistant bacterium Deinococcus radiodurans, enhances tolerance to hydrogen peroxide ($H_2O_2$) stress when expressed in Escherichia coli. A protein profile comparison showed that E. coli cells overexpressing D. radiodurans Hsp20 (EC-pHsp20) activated the redox state proteins, thus maintaining redox homeostasis. The cells also showed increased expression of pseudouridine (psi) synthases, which are important to the stability and proper functioning of structural RNA molecules. We found that the D. radiodurans mutant strain, which lacks a psi synthase (DR0896), was more sensitive to $H_2O_2$ stress than wild type. These suggest that an increased expression of proteins involved in the control of redox state homeostasis along with more stable ribosomal function may explain the improved tolerance of EC-pHsp20 to $H_2O_2$ stress.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.92-98
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• 2021

The effects of heat-moisture treatment (HMT) on rice flour (RF) have been investigated for possibility of texture modifier in protein-based foods matrix, tofu. The optimum condition for preparation of tofu with maximum textural parameters was investigated by using response surface methodology (RSM). Rice flour was subjected to moisture content (10-30%) and heating temperature (100-140℃). Based on the response surface and superimposed plots, the optimized conditions of hydrothermally treated rice flour was as followed: moisture content, 22%; temperature, 130℃, which showed lower swelling power as compared to native RF and became more stable during continuous heating and agitation than native one. Tofu, prepared with HMT-RF, showed a denser network structure than that with RF, thereby inducing an increase in textural parameters. From the above results, the addition of HMT-RF could preserve the quality of tofu and be useful for developing an acceptable protein-based food product.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.11-21
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• 2008

Aim of the study: Thermal stress is a central determinant of osseous surgical outcomes. Interestingly, the temperatures measured during endosseous surgeries coincide with the temperatures that elicit the heat shock response of mammalian cells. The heat shock response is a coordinated biochemical response that helps to protect cells from stresses of various forms. Several protective proteins, termed heat shock proteins (hsp) are produced as part of this response. To begin to understand the role of the stress response of osteoblasts during surgical manipulation of bone, the heat shock protein response was evaluated in osteoblastic cells. Materials & methods: With primary cell culture studies and ROS 17/2.8 osteoblastic cells transfected with hsp27 encoding vectors culture studies, the thermal stress response of mammalian osteoblastic cells was evaluated by immunohistochemistry and western blot analysis. Results: Immunocytochemistry indicated that hsp27 was present in unstressed osteoblastic cells, but not fibroblastic cells. Primarily cultured osteoblasts and fibroblasts expressed the major hsp in response to thermal stress, however, the small Mr hsp, hsp27 was shown to be a constitutive product only in osteoblasts. Creation of stable transformed osteoblastic cells expressing abundant hsp27 protein was used to demonstrate that hsp27 confers stress resistance to osteoblastic cells. Conclusions: The demonstrable presence and function of hsp27 in cultured bones and cells implicates this protein as a determinant of osteoblastic cell fate in vivo.

• BMB Reports
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• v.41 no.5
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• pp.382-387
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• 2008

It is known that the stable protein 1 (SP1) detected in aspen plants remains soluble upon boiling and that sp1 expression in transgenic aspen is resistant to salt stress. Presently, we analyzed the effect of expression of SP1 in Arabidopsis thaliana plants and their response to high temperature stress. After $45^{\circ}C$ for 16 h, relative to wild type plants, sp1 transgenic plants exhibited stronger growth and were better in several physiological properties including chlorophyII, chlorophyII fluorescence, water content, proline content, and malondialdehyde content. These preliminarily results suggest that the over-expression of SP1 may notably enhance heat-tolerant level of transgenic A. thaliana plants.

• BMB Reports
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• v.31 no.2
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• pp.130-134
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• 1998

An aldolase gene has been cloned from Methanococcus jannaschii. The coding region of the gene has been expressed in E. coli using a pET system to a level of 30% of total cellular proteins. The protein was purified to more than 95 % homogeneity by heat treatment and ion exchange chromatography. The protein performed an aldol condensation reaction with glyceraldehyde as substrate and dihydroxyacetone phosphate as a carboxyl donor. The protein was determined to be a type II aldolase which requires the $Zn^{2+}$ ion as a metal cofactor. This enzyme has a broad range of optimum pH (7-9) and temperature ($50-80^{\circ}C$). It shows strong stability against heat, chemical denaturants, as well as a high percentage' of organic solvents. The half-life of this enzyme at $85^{\circ}C$ is more than 24 h and it maintains more than 90% of aldolase activity in the presence of 6 M urea, 50% acetonitrile, or 15% isopropyl alcohol.