• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.367-376
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• 2014

Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with $GRA2_{25-105}$, $GRA3_{39-138}$, $ROP2_{324-561}$, and $MIC2_{1-284}$ domains had respectively higher value of IgG avidity. The $rGST-GRA2_{25-105}$ and $rGST-GRA3_{39-138}$ were soluble, while $rGST-ROP2_{324-561}$ and $rGST-MIC2_{1-284}$ were not. $GRA2_{31-71}$, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The $rGST-GRA2_{31-71}-ROP2_{324-561}$, a chimeric protein, appeared to be soluble. Moreover, $rGST-GRA2_{31-71}-MIC2_{1-284}$ was also soluble and had higher IgG avidity comparing to $rGST-MIC2_{1-284}$. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.73-77
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• 2006

Ground pork was irradiated with an electron beam (e-beam) at a dose of 0, 1.5, 3, 5 and 10 kGy and the changes in various functional and other associated properties of salt-soluble proteins extracted from the pork were evaluated. Irradiation did not affect turbidity and the disulfide content of pork salt-soluble protein, but the content of sulfhydryls and the hydrophobocity of salt-soluble protein increased. This indicates that protein degradation occurred when the pork was e-beam irradiated and that the sulfhydryls and hydrophobic moieties buried inside the proteins were exposed to the outside environment. However, these degraded protein molecules did not form large protein aggregates through disulfide bridges. The emulsifying capacity of the pork increased with irradiation, which could be the result from increased hydrophobicity of pork salt-soluble protein. Water holding capacity of pork was not affected bye-beam irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.180-185
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• 1997

This work was carried out to investigate change of polygalacturonase activities and polygalacturonase patterns by gel filtration chromatography during softening of persimmon and jujube fruits. During softening of two kinds of fruit, polygalacturonase activities of water-soluble and salt-soluble proteins were increased, but that of cell wall-bound proteins was decreased. In water-soluble and salt-soluble proteins of persimmon fruits, two peaks of polygalacturonase activity were separated in mature stages, but one peak in soft stages. During softening of those fruits, the peaks of polygalacturonase activity in water-soluble and salt-soluble proteins appeared on the same fraction with the peaks of polygalacturonase activity in cell wall-bound proteins.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.643-654
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• 2019

The amino acid composition, protein quality, and protein functionality of protein solution extracted from three edible insect species were investigated. We used 0.02% ascorbic acid and 0.58 M saline solution to extract water-soluble and salt-soluble proteins from the three insect species. Extracted protein solutions of Tenebrio molitor (TM), Allomyrina dichotoma (AD), and Protaetia brevitarsis seulensis (PB) were divided into six groups, according to species and solubility: WTM, WAD, WPB (water-soluble), and STM, SAD, and SPB (salt-soluble). Defatted TM had the highest protein content, but its protein solubility was the lowest, for both water and saline solutions. Amino acid composition differed by edible insect species and buffer type; SPB had the highest protein quality, followed by WPB. PB had a higher pH than the other species. Color values also differed among species. SPB had abundant high molecular weight proteins, compared with other treatments; and also had the highest foaming capacity, foam stability, and emulsifying capacity. In conclusion, PB is a good source of functional protein compared with the other studied species. Additionally, protein extraction using saline solution is promising as a useful method for improving edible insect protein functionality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.175-179
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• 1997

Changes of protein contents and chromatogram patterns by gel filtration chromatography was investigated for the purpose of studying changes of Proteins during softening of persimmon and jujube fruits. Contents of water-soluble and salt-soluble proteins were increased during softening of persimmon and jujube fruits, but that of cell wall-bound proteins was decreased. After performing a gel filtration of water-soluble protein, one peak was separated in mature persimmon fruits and three peaks in soft persimmon fruits. In the case of jujube fruits, there were three peaks in both of mature and soft fruits. Pattern of salt-soluble and cell wall-bound proteins by gel filtration chromatography hardly changed during softening. During softening of two fruits, the contents of water- soluble and salt-soluble proteins appeared to be increased on the same fractions with the decreasing in content of cell wall-bound proteins.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.889-894
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• 2009

Barley proteins are expected to have unique functional properties due to their high content of alcohol soluble protein, hordein. Since the barley proteins obtained by conventional isoelectric precipitation method cannot represent hordein fraction, barley proteins were fractionated to albumin, globulin, glutelin, and hordein with respect to extraction solvents. Functional properties and film-forming properties of solubility-fractionated barley proteins were investigated to explore their potential for human food ingredient and industrial usage. The 100 g of total barley protein comprised 5 g albumin, 23 g globulin, 45 g glutelin, and 27 g hordein. Water-binding capacities of barley protein isolates ranged from 140-183 mL water/100 g solid. Hordein showed the highest oil absorption capacity (136 mL oil/100 g), and glutelin showed the highest gelation property among the fractionated proteins. In general, the barley protein fractions formed brittle and weak films as indicated by low tensile strength (TS) and percent elongation at break (E) values. The salt-soluble globulin fraction produced film with the lowest TS value. Although films made from glutelin and hordein were dark-colored and had lower E values, they could be used as excellent barriers against water transmission.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.395-401
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• 2001

Crystallins are a family of water-soluble proteins that constitute up to 90% of the wa-ter-soluble proteins in mammalian eye lenses, We present in this paper an alternative purification method for these proteins using polyethylene glycol/dextran aqueous two-phase extraction. Un-der the appropriate conditions, we were able to recover the γ-crystallin fraction essentially free of the remaining proteins. High concentrations of salt at a neutral pH maximize the recovery of γ-crystallins in the top phase and minimize the contamination by the other proteins present in the lenses. The proposed protocol decreases the separation time by about 50%. The complex partition behavior observed for these proteins reflects a delicate balance between protein/phase-forming species(various polymers and salts) and protein interactions. This is evidenced, in part, by the role played by the largest proteins in this group as a "pseudo"phase-forming species.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.305-313
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• 1994

Typically susceptible lesions were developed on pepper (cv. Hanbyul) leaves inoculated with the compatible strains Ds 1 of Xanthomonas campestris pv. vesicatoria. The lesions appeared first water-soaked and then turned yellow with a chlorotic area. In contrast, the leaves inoculated with the incompatible strain 81-23 initially turned yellow and then developed local necrosis. Multiplication of x. c. pv. vesicatoria in pepper leaves also were distinctly different between the two strains. The strain Ds 1 multiplied more greatly than did the strain 81-23 in the infected leaves. X. c. pv. vesicatoria infection of pepper leaves induced the synthesis of soluble proteins, especially more greatly in the compatible than in the incompatible interactions. Some pathogenesis-related (PR) proteins were detected in the intercellular washing fluid (IWF) and extracts of the infected pepper leaves. In particular, the 32 kDa protein on SDS-PAGE gels appeared intensely in the incompatible interaction. In contrast, some proteins with moluecular masses of 65, 71, and 75 kDa disappeared in the infected pepper leaves. Isoelectric focusing could identify the pIs of soluble proteins in infected pepper leaves. The accumulation of the IWF from infected leaves was more conspicuous in the incompatible than the compatible interaction. These results suggest that some extremely acidic and basic proteins were induced and accumulated in the intercellular spaces of infected pepper leaves.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.53-60
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• 1995

Inoculation with the compatible strain Ds 1 of Xanthomonas campestris pv. vesicatoria caused brownish ad water-soaked lesions, but incompatible strain Bv5-4a produced hypersensitive symptoms with local necrosis on tomato (cv. Kwangyang) leaves. Bacterial populations of the compatible strains Ds 1 propagated more greatly than the incompatible strain Bv5-4a at the frist onset, but no differences were observed 5 days after inoculation. The bacterial infection induced the synthesis and accumulation of soluble proteins in tomato leaves, especially in the incompatible interaction. Native-polyacrylamide gel electrophoresis distinguished the soluble proteins in the tomato leaves infected by the compatible or incompatible strains. A protein of low molecular weight occurred only in the incompatible interaction. Some pathogenesis-related (PR) proteins, especially the 15, 18, 23, 26 and 54 kDa proteins, were detected only in the infected tomato leaves. In the two-dimensional electrophoresis, some proteins with different molecular weights (Mr. 21∼29 kDa) and the pI 8∼9 appeared more distinctly only in the incompatible interaction. These data suggest that the de novo synthesis of some PR proteins in tomato may be significant in defense against X. c. pv. vesicatoria.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.2
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• pp.86-97
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• 2024

Alkaline- or salt-assisted extractions have been widely used to extract edible insect proteins, however, there is a need for extraction techniques that balance cost-efficient production as well as preserving the protein properties. Mealworm proteins (Tenebrio molitor larvae) were extracted using three different extraction methods-alkali (AMP), salt (SMP), and water (WMP)-and then physicochemical and techno-functional properties were examined. AMP had high yield, protein, and amino acid contents, whereas WMP had high moisture, ash, and fat contents. SDS-PAGE showed a wide range of molecular weights in WMP whereas mostly low molecular weights were observed in AMP and SMP. AMP had poor protein solubilities compared to SMP and WMP across all pHs. AMP had enhanced water-holding capacity and emulsion stability, whereas WMP had improved oil-holding capacity and foaming properties. WMP formed a gel with and without the transglutaminase. The physicochemical and techno-functional properties demonstrated that water-soluble mealworm protein was superior to alkali-and salt-soluble mealworm proteins. Considering the cost efficiency and minimal impact on the environment as well, a cold press juicer could be utilized for mass production of mealworm protein compared to the conventional methods of protein extraction using alkali and salt.