• Toxicological Research
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• 제30권1호
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• pp.33-38
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• 2014

The human cytochrome P450 2J2 catalyzes an epoxygenase reaction to oxidize various fatty acids including arachidonic acid. In this study, three recombinant enzyme constructs of P450 2J2 were heterologously expressed in Escherichia coli and their P450 proteins were successfully purified using a $Ni^{2+}$-NTA affinity column. Deletion of 34 amino acid residues in N-terminus of P450 2J2 enzyme (2J2-D) produced the soluble enzyme located in the cytosolic fraction. The enzymatic analysis of this truncated protein indicated the typical spectral characteristics and functional properties of P450 2J2 enzyme. P450 2J2-D enzymes from soluble fraction catalyzed the oxidation reaction of terfenadine to the hydroxylated product. However, P450 2J2-D enzymes from membrane fraction did not support the P450 oxidation reaction although it displayed the characteristic CO-binding spectrum of P450. Our finding of these features in the N-terminal modified P450 2J2 enzyme could help understand the biological functions and the metabolic roles of P450 2J2 enzyme and make the crystallographic analysis of the P450 2J2 structure feasible for future studies.

• 대한의생명과학회지
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• 제13권4호
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• pp.341-347
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• 2007

Streptococcus mutans, one of a major causal agents of dental caries, is component of the dental plaque and produces various organic acids such as lactic acid as the end-product of glycolysis. In this study, we isolated S. mutans from Korean children with caries and also investigated the expression of protein under acid stress. S. mutans was identified at the species level using a 16S ribosomal DNA sequencing comparison method. The primer specificity was tested on eleven S. mutans strains isolated from Korean children with caries. The data showed that eleven strains are S. mutans. At treatment of concentration of 20 mM lactic acid in the mid-log phage, K-7 exhibited the highest maximum culture OD compared with those of other groups. As a consequence, we examined the expression of protein under 20 mM lactic acid stress using S. mutans K-7. The results of 2D gel electrophoresis by image analysis showed that thirteen proteins are up-regulated under the stress. Further study is being focused on amino acid analysis by mass spectrometry in order to analyze those spots.

• BMB Reports
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• 제34권4호
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• pp.334-341
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• 2001

Even though three isotypes of thioredoxins (-f, -m and -h types) have been identified in a variety of plant cells, there are only a few reports on thioredoxin-h that were recently identified. In this study, a cDNA encoding a h-type of thioredoxin was isolated from a cDNA library of Chinese cabbage, and named here CTrx-h. An open reading frame of the gene contained a polypeptide of 133 amino acids with a conserved active center, WCGPC, which appeared in all of the thioredoxin proteins. A deduced amino acid sequence of the CTrx-h showed the highest sequence identity with those of Arabidopsis thioredoxin-h2 (75.2%) and thioredoxin-h5 (46.6%) proteins, but it shared a low sequence homology to other isotypes of plant thioredoxinm and thioredoxin-f. The CTrx-h protein that is expressed in E. coli represented not only an insulin reduction activity, but also electron transferring activity from NADPH to thioredoxin-dependent peroxidase. A genomic Southern blot analysis using the cDNA insert of CTrx-h revealed that the gene consisted of a small multigene family in Chinese cabbage genome. On the contrary to other thioredoxin-h proteins that were widely distributed in most tissues of the plant, the CTrx-h was predominantly expressed in flowers. The expression was very low in other tissues. The data of the Northern blot analysis suggests that the CTrx-h may have other functions in flower development or differentiation, in addition to its defensive role.

• International Journal of Industrial Entomology and Biomaterials
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• 제45권2호
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• pp.84-92
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• 2022

White-Jade silkworm (previously also known as Baegokjam) variety is the most popular silkworm variety that produces white cocoons. In 2021, the market share of White-Jade variety in Korea is very high, accounting for 88% of the silkworm production. Daebaekjam, Dodamsilkworm, Kumkangjam, and Kumokjam varieties, which have recently been established, make white cocoons like White-Jade. In this study, we found that 5 types of HongJams produced from 5 varieties of silkworms producing white cocoons did not show any severe difference in proximate analysis. The amounts of crude proteins, the most abundant nutrient, were between 71.05 ~ 73.38%, and those of crude lipids were 13.89 ~ 14.69% in 5 types of HongJams. In addition, there was no difference between White-Jade HongJam (WJ) and Daebaekjam HongJam in amino acid compositions. The amount of unsaturated fatty acid was significantly higher in WJ than in the other four types of HongJams, but the omega-6 fatty acids/omega-3 fatty acids ratio was higher in the four types of HongJams. Most of the minerals were higher in four types of HongJams than in WJ, and three heavy metal were not detected in all 5 types of HongJams. Phytochemicals were also most abundant in WJ, but the difference in the amounts were not severe. And pepsin digestibility was the highest for Kumokjam HongJam and the lowest for Dodam-silkworm HongJam, but the difference was not severe. The nutritional component analysis results of this study suggested that four new varieties can be used for producing HongJams, and Daebaekjam can replace White-Jade the most as the protein source.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 2002년도 제54회 춘계심포지움 - 우유와 국민건강
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• pp.59-60
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• 2002

Edible films such as wax coatings, sugar and chocolate covers, and sausage casings, have been used in food applications for years$^{(1)}$ However, interest in edible films and biodegradable polymers has been renewed due to concerns about the environment, a need to reduce the quantity of disposable packaging, and demand by the consumer for higher quality food products. Edible films can function as secondary packaging materials to enhance food quality and reduce the amount of traditional packaging needed. For example, edible films can serve to enhance food quality by acting as moisture and gas barriers, thus, providing protection to a food product after the primary packaging is opened. Edible films are not meant to replace synthetic packaging materials; instead, they provide the potential as food packagings where traditional synthetic or biodegradable plastics cannot function. For instance, edible films can be used as convenient soluble pouches containing single-servings for products such as instant noodles and soup/seasoning combination. In the food industry, they can be used as ingredient delivery systems for delivering pre-measured ingredients during processing. Edible films also can provide the food processors with a variety of new opportunities for product development and processing. Depends on materials of edible films, they also can be sources of nutritional supplements. Especially, whey proteins have excellent amino acid balance while some edible films resources lack adequate amount of certain amino acids, for example, soy protein is low in methionine and wheat flour is low in lysine$^{(2)}$. Whey proteins have a surplus of the essential amino acid lysine, threonine, methionine and isoleucine. Thus, the idea of using whey protein-based films to individually pack cereal products, which often deficient in these amino acids, become very attractive$^{(3)}$. Whey is a by-product of cheese manufacturing and much of annual production is not utilized$^{(4)}$. Development of edible films from whey protein is one of the ways to recover whey from dairy industry waste. Whey proteins as raw materials of film production can be obtained at inexpensive cost. I hypothesize that it is possible to make whey protein-based edible films with improved moisture barrier properties without significantly altering other properties by producing whey protein/lipid emulsion films and these films will be suitable far food applications. The fellowing are the specific otjectives of this research: 1. Develop whey protein/lipid emulsion edible films and determine their microstructures, barrier (moisture and oxygen) and mechanical (tensile strength and elongation) properties. 2. Study the nature of interactions involved in the formation and stability of the films. 3. Investigate thermal properties, heat sealability, and sealing properties of the films. 4. Demonstrate suitability of their application in foods as packaging materials. Methodologies were developed to produce edible films from whey protein isolate (WPI) and concentrate (WPC), and film-forming procedure was optimized. Lipids, butter fat (BF) and candelilla wax (CW), were added into film-forming solutions to produce whey protein/lipid emulsion edible films. Significant reduction in water vapor and oxygen permeabilities of the films could be achieved upon addition of BF and CW. Mechanical properties were also influenced by the lipid type. Microstructures of the films accounted for the differences in their barrier and mechanical properties. Studies with bond-dissociating agents indicated that disulfide and hydrogen bonds, cooperatively, were the primary forces involved in the formation and stability of whey protein/lipid emulsion films. Contribution of hydrophobic interactions was secondary. Thermal properties of the films were studied using differential scanning calorimetry, and the results were used to optimize heat-sealing conditions for the films. Electron spectroscopy for chemical analysis (ESCA) was used to study the nature of the interfacial interaction of sealed films. All films were heat sealable and showed good seal strengths while the plasticizer type influenced optimum heat-sealing temperatures of the films, 130$^{\circ}$C for sorbitol-plasticized WPI films and 110$^{\circ}$C for glycerol-plasticized WPI films. ESCA spectra showed that the main interactions responsible for the heat-sealed joint of whey protein-based edible films were hydrogen bonds and covalent bonds involving C-0-H and N-C components. Finally, solubility in water, moisture contents, moisture sorption isotherms and sensory attributes (using a trained sensory panel) of the films were determined. Solubility was influenced primarily by the plasticizer in the films, and the higher the plasticizer content, the greater was the solubility of the films in water. Moisture contents of the films showed a strong relationship with moisture sorption isotherm properties of the films. Lower moisture content of the films resulted in lower equilibrium moisture contents at all aw levels. Sensory evaluation of the films revealed that no distinctive odor existed in WPI films. All films tested showed slight sweetness and adhesiveness. Films with lipids were scored as being opaque while films without lipids were scored to be clear. Whey protein/lipid emulsion edible films may be suitable for packaging of powder mix and should be suitable for packaging of non-hygroscopic foods$^{(5,6,7,8,)}$.

• KSBB Journal
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• 제23권5호
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• pp.425-430
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• 2008

생체에서의 황화수소는 의약 분야와 발효 산업에 있어서 중요한 역할을 하고 있다. 본 연구에서는 Saccharomyces cerevisiae을 이용하여 기질인 L-cysteine과 $\beta$-mercaptoethanol로부터 $\beta$-replacement 반응에 인한 황화수소를 발생시킬 수 있는 효소를 간편하고 신속하게 동정하는 방법의 확립을 목적으로 하였다. 효소에 의해 발생된 황화수소와 Pb-acetate의 반응으로 생성된 Pb-S를 gel상에서 간편하게 확인한 후, 확인된 단백질들을 이온교환컬럼를 수행한 후 gel에서 추출하는 방법으로 MALDI-TOFMS의 시료를 간단히 얻을 수 있었다. PMF 방법과 MS/MS ion search 분석을 통해 간편하게 효모에서 황화수소를 형성할 가능성이 있는 세가지 단백질의 동정에 성공하였다. 이 세 가지 단백질은 CYS3, CYS4, MET17 유전자의 단백질로서 cystathionine $\gamma$-lyase, CBS, OASS 임이 밝혀졌다. 그리고 이 세 단백질들은 L-cysteine과 $\beta$-mercaptoethanol의 존재하에서 황화수소를 실제로 생성함을 확인하였다. 본 연구에서 표적의 물질을 생산하는 단백질들을 젤상에서의 활성측정과 MALDI-TOF MS를 이용하여 간단히 그리고 정확하게 동정하는 방법을 확립하였다.

• Mycobiology
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• 제46권1호
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• pp.24-32
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• 2018

Improper disposal of herb residues in China has caused severe problems to the surrounding environment and human safety. Three herb residues, i.e., compound Kushen injection residues (CKI) and part one and part two of Qizhitongluo Capsule residues (QC1 and QC2, respectively), were used for the cultivation of Pleurotus ostreatus. The effect of the supplementation of corncobs (CC) with different herb residues on yield, nutritional composition, and antioxidant activity of P. ostreatus was investigated. Compared to the control, the higher mycelial growth rate was observed on substrates CC +30% CKI and CC +30% QC1, while the higher yield was obtained from substrates CC +30% QC2 and CC +30% CKI. Moreover, chemical analysis of fruit bodies revealed that the addition of herb residues to CC significantly increased proteins, amino acids, ashes, minerals (Na and Ca), and total phenolic contents but significantly reduced carbohydrates and $IC_{50}$ values of DPPH radicals. In addition, no heavy metals (Pb, Cd, and As) were detected in the fruiting bodies harvested from different substrate combinations. These results demonstrated that mixtures of CC with herb residues might be utilized as a novel, practical, and easily available substrate for the cultivation of P. ostreatus, which is beneficial for the effective management of herb residues.

• Clinical and Experimental Vaccine Research
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• 제13권2호
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• pp.146-154
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• 2024

Purpose: Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5. Materials and Methods: Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted. Results: The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite. Conclusion: In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.

• 한국수산과학회지
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• 제18권6호
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• pp.550-556
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• 1985

수산무척추동물에 속하는 개불과 군소의 식품학적 평가를 위하여 육의 단백질 및 아미노산조성을 분석 검토하였으며, in vitro법에 의한 단백질의 품질추정을 위한 실험도 병행하였다. 개불과 군소의 육은 각각 $10.19\%$와 $6.33\%$의 조단백질을 함유하고 있었다. 이들 각 육은 개불에 있어서는 비단백태질소;$40.6\%$, 수용성단백질 ; $58.9\%$ 염용성단백질 ; $0.2\%$, 알칼리가용성단백질 ; $0.2\%$ 및 기질단백질 ; $0.1\%$, 그리고 군소에 있어서는 비단백태질소 ; $38.8\%$, 수용성단백질 ; $56.9\%$, 염용성단백질 ; $2.5\%$, 알칼리가용성단백질 ; $1.6\%$ 및 기질단백질 ; $0.2\%$로 구성되어 있었다. 양적으로 많은 비율을 점하는 수용성단백질의 subunit 조성을 측정한 결과, 개불은 15개 subunit, 군소는 10개 subunit가 검출되었다. 유리아미노산의 조성을 분석한 결과, 개불은 glycine과 alanine 이 총유리아미노산의 약 $75\%$를 차지 하였고, glycine, alanine, taurine, arginine 및 aspartic acid는 총유리아미노산의 약 $96\%$를 차지하였다. 군소의 총유리아미노산의 양은 개불의 총유리아미노산양의 약 1/10에 불과하였으며 taurine이 총유리아미노산의 약 $78\%$를 차지하였다. 단백질의 아미노산조성을 분석한 결과, 개불의 육단백질에는 glycine, aspartic acid, glutamic acid, arginine, lysine이 많이 함유되어 있었고 cysteine은 그 함량이 적었다. 그리고, 군소의 육단백질에는 glycine, glutamic acid, aspartic acid, arginine이 많이 함유되어 있었으며 cysteine과 tryptophan은 흔적양에 불과하였다. 한편, 개불과 군소육의 가수분해 시료중에는 개불은 glutamic acid, aspartic acid, glycine, arginine, leucine이 그리고 군소는 glycine, glutamic acid, aspartic acid, leucine, serine이 비교적 많은 함량을 보였다. in vitro 법으로 이들 두 동물의 육단백질의 영양가를 추정한 결과, 이미 알려진 수산동물의 육단백질에 비하여 떨어짐을 알 수 있었다.

• 한국수산과학회지
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• 제14권1호
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• pp.15-23
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• 1981

말쥐치 등육 골낙근을 $0^{\circ}C$로 유지하면서 사후경과중 선도의 변화에 따라 단백질의 조성과 단백질의 아미노산 조성 및 유리아미노산의 조성 등을 분석 검토하였다. 말쥐치의 육은 약 $20\%$의 단백질을 함유하고 있었으며, 이 단백질은 근원질단백질 $31\%$, 근원섬유단백질 $55\%$, 세포내잔사단백질 $10\%$, 그리고 기질단백질 $4\%$로 구성되어 있었다. 근원질단백질과 근원섬유단백질은 사후선도의 변화와 더불어 감소하여 갔고, 세포내잔사단백질은 상대적으로 증가하는 관계를 보였다. 근원섬유단백질과 세포내잔사단백질은 전기영동과 densitometry에 의하여 분석한 결과, 근원섬유단백질의 약 $70\%$가 액틴과 미요신, 약 $20\%$가 조절단백질, 그리고 $10\%$전후의 미지단백질로 구성되어 있었다. 세포내잔사단백질은 그 대부분이 근원섬유단백질을 구성하는 단백질로 이루어져 있었다. 한편, 사후경과와 더불어 근원섬유단백질을 구성하는 단백질중 트로포닌-T, 트로포닌-C 및 미요신의 light chain 2는 각각 감소하는 추세를 보였다. 죽인 직후의 말쥐치 육단백질의 아미노산 조성은 다른 어육의 그것과 비슷하였으나, 트?토판과 함황아미노산은 보다 부족하였다. 휘발성 염기질소양에비추어 부패초기에 해당하는 사후 18일이 경과했을 때는 프롤린과 시스테인이 두드러지게 줄었으며, 로이신과 이소로이신 및 페닐알라닌은 조금 증가하였다. 말쥐치육의 유리아미노산중에는 타우린이 특히 많이 함유되어 있었으며, 알라닌과 글리신 및 리신도 비교적 많았다. 사후 18일이 경과했을 때는 타우린, 히스티딘, 발린 및 메치오닌은 증가하였으나 리신, 아르기닌, 아스파르트산, 스레오닌, 세린, 로이신 및 이소로이신은 반대로 감소하였다.