• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.718-724
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• 2017

The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

• 한국식품영양학회지
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• 제9권3호
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• pp.325-330
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• 1996

Foaming capacity (FC) and stability (FS) of protein recovered from red crab (Chitinonecetes opilio) processing in water and soybean protein isolate were determined at pH 2.0~10.0 in water and NaCl solution. The FC values for both proteins showed the lowest values at the isoelectric point (pH 4.0) and increased nth an increase in pH above the isoelectric point. FC of RCP was higher than that of SPI at pH 10.0 in water and both NaCl solutions. FC of SPI increased with an increase in NaCl concentration at pH 4.0 and 6.0, but FC of RCP was not affected. The highest FS values for both proteins were obtained at pH 4.0 in water. At pH 2.0, FC of RCP decreased with NaCl concentration increase, but FS increased. NaCl concentration had little effect on FS of RCP at pH 4.0 and 6.0, but the FS decreased at pH 10.0. FS of SPI was similar to that of RCP at pH 2.0 and increased with NaCl concentration Increase from 0.1 to 0.5M NaCl at pH 10.0.

• 한국축산식품학회지
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• 제39권3호
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• pp.494-502
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• 2019

The quality characteristics and storage stability of chicken breast meat (CBM) was investigated following the injection of whey protein (WP) as a curing ingredient. The moisture content of CBM decreased with increasing concentration of WP. The highest concentration of WP (7%) resulted in the lowest moisture and fat content and the highest protein content of CBM. Injection of WP elevated the pH and water holding capacity (WHC) of CBM. The cooking loss of CBM was significantly decreased with WP injections of 3% and higher. All WP injections increased the $L^*$ of the CBM but decreased the $a^*$ and $b^*$. WP injection increased the springiness, cohesiveness, and chewiness and decreased the hardness of the CBM. WP injection increased 2-thiobarbituric acid reactive substances (TBARS) after 3 and 7 days of storage. The volatile basic nitrogen (VBN) content of the CBM increased with increased concentrations of WP. The total microbial count (TMC) of CBM injected with WP was higher initially and after 3 days of storage. Our results showed WP injection improved the WHC of CBM but decreased the storage stability by increasing TBARS, VBN and TMC.

• 한국축산식품학회지
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• 제42권5호
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• pp.889-902
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• 2022

With increasing consumer demand for "clean label" products, the use of natural ingredients is required in the food industry. Protein/polysaccharide complexes are considered good alternatives to synthetic emulsifiers and stabilizers for formulating stable emulsion-based foods. Milk protein and carrageenan are widely used to improve the physical properties and stability of dairy food products. In a previous study, milk protein isolate (MPI) was conjugated with 𝛋-carrageenan (𝛋-Car) in a wet-heating system through the Maillard reaction, and the Maillard conjugates (MC) derived from MPI and 𝛋-Car effectively improved the stability of oil-in-water emulsions. Therefore, MPI/𝛋-Car conjugates were used in whipping cream as natural emulsifiers in this study, and the physical and rheological properties of whipping creams stabilized using MPI/𝛋-Car MC and MPI/𝛋-Car electrostatic complexes (EC) were investigated. The whipping creams stabilized with MPI/𝛋-Car MC have lower rheological parameters (η_a,50, K, G', and G'') than those of whipping creams stabilized with MPI/𝛋-Car EC. Although the overrun value was slightly reduced owing to the addition of MPI/𝛋-Car MC, the stability of the whipped creams with MC was effectively improved due to enhanced water-holding ability by conjugation.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.275-280
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• 2010

Actinobacillus actinomycetemcomitans is a gram-negative, nonmotile coccobacillus bacterium that is associated with several human diseases, including endocarditis, meningitis, osteomyelitis, subcutaneous abscesses and periodontal diseases. A full-length Omp1-like protein gene from A. actinomycetemcomitans was cloned into a pQE30 vector and overexpressed in Escherichia coli BL21(DE3) cells. The protein revealed sequence homologies to Seventeen kilodalton proteins (Skp) from Pasteurella multocida and E. coli that have been characterized as periplasmic chaperones. This soluble Omp1-like protein was successfully purified to homogeneity for further folding and functional studies. The purity, identity, and conformation of the protein were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization mass spectrometry, circular dichroism, fluorescence spectroscopic, and differential scanning calorimetric studies. We showed that the protein formed an oligomer larger than a tetramer. We found, further, that it is comprised of mostly $\alpha$-helices and boasts high thermal stability.

• 한국식품조리과학회지
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• 제20권3호
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• pp.256-264
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• 2004

The effects of irradiation on the functional and structural characteristics of soy protein isolates were studied. Soymilk was irradiated at 1, 5, and l0kGy, after which soy protein isolates were prepared. The functional properties of soy protein isolates were examined including solubility, emulsion capacity and stability, foam capacity and stability, structural properties as represented by SDS-PAGE pattern, and secondary and tertiary structures. The solubility and emulsion capacity were increased by radiation treatment at 1kGy however the values were adversely affected again as dosage was increased above 5kGy. As irradiation dosage increased, an increase of foaming capacity at 1kGy and a decreasing turnover afterwards were also noted in foaming capacity, although the differences were not statistically significant. The SDS-PAGE pattern showed fragmentation and aggregation of protein molecules as affected by irradiation in proportion to the dosage increase. The results of CD and fluorescence spectroscopy revealed increased aperiodic structure contents with the dosage increase. It was assumed that irradiation dosagefrom 5 to l0kGy could initiate minimal denaturation of protein in various foods compared to general heat treatment.

• 한국식품영양과학회지
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• 제27권1호
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• pp.46-50
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• 1998

폐단백질을 활용하는 방도의 하나로 폐단백질자원으로부터 토양에서 분리한 Aspergillus sp. 균주가 생산하는 phytase를 이용하여 불용성 단백질의 분리 효율성을 높였으며 추출 단백질의 기능성을 살펴보았다. 참깨박에 함유되어 있는 불용성 형태의 단백질을 가용성 형태의 단백질로 용출시키기 위한 최적 pH, 최적 온도, 최적 처리시간과 최적 첨가효소량은 4.0~5.0, $50^{\circ}C$, 8~10시간, 120unit였고, 효소처리된 참깨박은 phytase 처리의 경우 대조구에 비해 기포형성력은 크게 증가하지 않았으나 기포안정성은 다소 증가하였다. 참깨박 단백질의 유화력은 다소의 유화력과 안정성의 증가가 관찰되었고, 유지흡착력과 수분흡착력은 대조구에 비해서 높은 값을 나타내었다.

• 한국식품과학회지
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• 제18권3호
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• pp.204-209
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• 1986

번데기 단백질의 이용성을 증진시킬 목적으로 농축 단백질을 조제하여 중요한 성질인 기능성을 대두 단백질과 비교하였다. 번데기 농축단백질은 대두 농축단백질보다 지방 흡수력이 더 높았으며, 용해도와 수분 흡수력은 낮았다. 유화성은 62.8%로 번데기 농축단백질이 더 높았으며, 유화력도 307ml/g으로 역시 높게 나타났다. 또한 $80^{\circ}C$로 가열한 후의 유화안정성도 번데기 농축단백질이 65.8%로 대두 농축단백질보다 더 높게 나타났다. 포말성은 번데기 농축단백질이 더 낮았으며 포말안정성은 달걀알부민보다, 번데기, 대두 농축단백질이 더 낮았고, $5{\sim}7%$사이에 점도 증가 현상이 크게 나타났다. 이상의 실험결과에서 나타난 번데기 농축단백질의 높은 지방 흡수력과 유화성은 유화력을 이용한 식품제조에 좋은 단백질원으로서 이용이 가능하리라고 사료된다.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.53-58
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• 1996

The characterstics of the soy protein curd(eczyme-, HCI- and Ca-surd) were shown by scanning electron micrographs and gel electrophoreis. The emulsion stability of enzyme-curd showed high value in the range of pH 2~10and wide range of temperature(20~8$0^{\circ}C$). While at the isoelectric point(pH5.0), the emulsion stability of the HCI-and Ca-curd was decreased remarkably, and the emulsion stability of temperature was reduced quickly to the 60% and 40% at the 4$0^{\circ}C$. The foam stability of enzyme-curd was slightly higher than that HCI-and CA-curd in all ranges of pH and temperature. The feature of SEM of enzyme-cured produced degradation products faster than that of the HCI- and Ca-curd.

• BMB Reports
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• 제50권6호
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• pp.329-334
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• 2017

Protein tyrosine phosphatases (PTPs) play crucial roles in signal transduction and their functional alteration has been detected in many diseases. PTP inhibitors have been developed as therapeutic drugs for diseases that are related to the activity of PTPs. In this study, PTP inhibitor XIX, an inhibitor of CD45 and PTEN, was investigated whether it inhibits other PTPs. Protein tyrosine phosphatase non-receptor type 2 (PTPN2) was selectively inhibited by the inhibitor in a competitive manner. Drug affinity responsive target stability (DARTS) analysis showed that the inhibitor induces conformational changes in PTPN2. Phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) at Tyr-705, a crucial site for STAT3 activation and target site of PTPN2, decreased upon exposure to the inhibitor. Our results suggest that PTP inhibitor XIX might be considered as an effective regulator of PTPN2 for treating diseases related to PTPN2.