• BMB Reports
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• 제52권6호
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• pp.397-402
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• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) uses the spike (S) glycoprotein to recognize and enter target cells. In this study, we selected two epitope peptide sequences within the receptor binding domain (RBD) of the MERS-CoV S protein. We used a complex consisting of the epitope peptide of the MERS-CoV S protein and CpG-DNA encapsulated in liposome complex to immunize mice, and produced the monoclonal antibodies 506-2G10G5 and 492-1G10E4E2. The western blotting data showed that both monoclonal antibodies detected the S protein and immunoprecipitated the native form of the S protein. Indirect immunofluorescence and confocal analysis suggested strong reactivity of the antibodies towards the S protein of MERS-CoV virus infected Vero cells. Furthermore, the 506-2G10G5 monoclonal antibody significantly reduced plaque formation in MERS-CoV infected Vero cells compared to normal mouse IgG and 492-1G10E4E2. Thus, we successfully produced a monoclonal antibody directed against the RBD domain of the S protein which could be used in the development of diagnostics and therapeutic applications in the future.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.780-786
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• 2002

An immunosensor based on surface plasmon resonance (SPR) with a self-assembled protein G layer was developed for the detection of Escherichia coli O157:H7. A self-assembled protein C layer on a gold (Au) surface was fabricated by adsorbing the mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol at various molar ratios and by activating chemical binding between free amine (-$NH_2$) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) in series. The formation of a self-assembled protein G layer on an Au substrate and the binding of the antibody and antigen in series were confirmed by SPR spectroscopy. The surface morphology analyses of the self-assembled protein G layer on the Au substrate, monoclonal antibody (Mab) against E. coli O157:H7 which was immobilized on protein G, and bound E. coli O157:H7 extracts on Immobilized Mab against E. coii O157:H7 were performed by atomic force microscopy (AFM). The detection limit of the SPR-based immunosensor for E. coli O157:H7 was found to be about $10^4$ cells/ml.

• 대한지역사회영양학회지
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• 제2권4호
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• pp.523-529
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• 1997

This study was conducted to obtain accurate data on the intake, digestibility and nitrogen balance of protein in Korean college women. Subjects were 8 female college students, aged from 21 to 23, and maintained their menu and life patterns regular during a 4- week study. The same amount of diet that the subjects had consumed, and feces and urine were collected and measured to extract their nitrogen content by Kjeldahl method. From this data, apparent digestibility and the body nitrogen balance were estimated by determing daily protein intake and excretion. The daily protein intake was 56.9$\pm$1.4g and daily fecal protein loss was 6.3$\pm$0.2g. The apparent digestibility of protein was 89.6$\pm$0.7$\%$. The daily nitrogen intake measured by Kjeldahl method was 9.43$\pm$0.2g. The urinary nitrogen excretion was 7.64$\pm$0.23g and fecal nitrogen excretion was 1.02$\pm$0.03g. The nitrogen balance indicated a positive balance of 0.45$\pm$0.18g. (Korean J Community Nutrition 2(4) : 523-529, 1997)

• Food Science and Biotechnology
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• 제18권4호
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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.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.514-521
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• 2019

G protein-coupled receptors (GPCRs) are membrane receptors whose agonist-induced dynamic conformational changes trigger heterotrimeric G protein activation, followed by GRK-mediated phosphorylation and arrestin-mediated desensitization. Cytosolic regions of GPCRs have been studied extensively because they are direct contact sites with G proteins, GRKs, and arrestins. Among various cytosolic regions, the role of helix 8 is least understood, although a few studies have suggested that it is involved in G protein activation, receptor localization, and/or internalization. In the present study, we investigated the role of helix 8 in dopamine receptor signaling focusing on dopamine D1 receptor (D1R) and dopamine D2 receptor (D2R). D1R couples exclusively to Gs, whereas D2R couples exclusively to Gi. Bioinformatic analysis implied that the sequences of helix 8 may affect GPCR-G protein coupling selectivity; therefore, we evaluated if swapping helix 8 between D1R and D2R changed G protein selectivity. Our results suggest that helix 8 is not involved in D1R-Gs or D2R-Gi coupling selectivity. Instead, we observed that D1R with D2R helix 8 or D1R with an increased number of hydrophobic residues in helix 8 relative to wild-type showed diminished ${\beta}$-arrestin-mediated desensitization, resulting in increased Gs signaling.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2000년도 춘계학술대회
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• pp.17-19
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• 2000

Heterotrimeric G Proteins transduce ligand binding to a wide variety of seven transmembrane cell surface receptors into intracellular signals. The currently accepted model for the activation of G protein suggests that ligand-activated receptor accelerates GDP-GTP exchange reactions on the ${\alpha}$ subunit of the heterotrimeric G protein. At least seventeen distinct isoforms of the G${\alpha}$ subunit protein have been identified in mammalian organisms. Among them, the G${\alpha}$q family consists of five members whose ${\alpha}$ subunits show different expression patterns. G${\alpha}$q and G${\alpha}$11 seem to be almost ubiquitously expressed, whereas G${\alpha}$14 is predominantly expressed in spleen, lung, kidney and testis. G${\alpha}$16 and its murine counterpart G${\alpha}$15 are expressed in hematopoietic cells and has been shown to couple a wide variety of receptors to phosphoinositide-specific phospholipase C activity. Beta-isoforms of phospholipase C were shown to be activated by all members of G${\alpha}$q family, i.e., G${\alpha}$q, G${\alpha}$11, G${\alpha}$l4 and G${\alpha}$16 subunits either in reconstitution system. or in experiments using cDNA transfection with intact Cos-7 cells.

• Journal of Nutrition and Health
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• 제24권2호
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• pp.124-131
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• 1991

식이 단백질 섭취수준 및 동·식물성 단백질 급원이 칼슘 및 인대사에 미치는 영향을 검토하기 위하여 10명의 한국성인 연성을 대상으로 26일간의 통제 식이실험을 실시하였다. 대사실험 연구는 6일간의 적응기간과 10일간의 중단백식이(60g 단백질 545mg Ca)와 10일간의 고단백질 식이(90g 단백질 575mg Ca)로 구성되었다 중·고단백 식이기간 동안 동물성 단백질(75% 동물성 단백질)과 식물성 단백질(75% 식물성 단백질) 식이군으로 나누어 같은 식이에서 중단백식이 후 고단백식이를 섭취토록 하였고 실험식이 마지막 4일간은 각 2명에게 300mg 칼슘을 보충시켰다. 칼슘 흡수율은 단백질 섭취량의 증가시 동물성 단백질 식이군에서 유의적으로 증가하였다, 칼슘 보충은 급원에 관계없이 칼슘 흡수를 증가시켰다. 중단백 식이기간 동안 동물성과 단백질 식이에서 칼슘흡수율은 약 30% 이었으며 고단백질식이 기간 동안 동물성 단백질에서 46% 식물성 단백질에서 37% 이었다. 칼슘을 보충시켰을 때 중단백 식이기간동안 칼슘 흡수율은 약 46% 이었으며 고단백 식이군에서 53%이었다 뇨중 칼슘배설은 단백질 섭취수준에는 영향을 받지 않았으나 동물성 단백질 식이에서 식물성 단백질 식이보다 칼슘배설양이 많았다. 칼슘 균형을 단백질 섭취증가와 칼슘 보충으로 호전되었다. 인의 흡수는 단백질 섭취수준에는 영향을 받지않았으며 인 섭취량에 따라 증가하였다. 인 흡수율은 동물성 단백질 식이군에서 약 77∼81% 로 식물성 단백질 식이군에서의 55∼65% 보다 높았다. 이상의 결과로 보아 단백질 섭취수준 60g에서 90g으로의 증가와 칼슘보충은 뇨중 칼슘 배설에는 영향을 주지않으며 칼슘 흡수를 증진시켜 칼슘균형을 호전시키는 것으로 나타났다.

• Journal of Nutrition and Health
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• 제36권9호
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• pp.942-949
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• 2003

This study was longitudinally conducted to evaluate the intakes of protein, Ca, Mg and P of exclusively breast-fed infants compared with the Recommended Dietary Allowances (RDA) for Korean infants. Twenty Korean lactating women and their infants during the first 3 months of lactation in Incheon area were participated. Protein, Ca and Mg, and P contents in the milk were determined using semimicro Kjeldahl (N ${\times}$ 6.38) , atomic absorption spectrophotometer and colorimeter, respectively, and also the milk consumption of the infants was measured by the test-weighing method. Protein contents of the milk were 1.96, 1.63, 1.51, 1.25 and 1.16 g/100 ml, and protein intakes of the breast-fed infants were 9.00, 9.85, 9.17, 8.97 and 7.76 g/day at 7, 15, 30, 60 and 90 days postpartum. The average protein intake per body weight of the breast-fed infants was 1.84 g/kg/day. The average intakes of Ca, Mg, P were 172.1 mg/day, 15.2 mg/day and 91.4 mg/day, respectively, and the average Ca/P ratio was 1.91. There was positive correlation between protein and Ca, protein and p, and Ca and P contents while negative correlation between Mg and P, The body weight of breast-fed infants increased normally from 3.6 $\pm$ 0.41 g at birth to three month during lactation. It is suggested that the breast-fed infants in Incheon area consume almost adequately protein, Ca and P from the milk compared with RDA for Korean infants.

• 미생물학회지
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• 제28권3호
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• pp.258-263
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• 1990

고도 카드뮴 내성 Hansenula anomale B-7으로부터 카드뮴 결합 단백질을 분리하여 전기 영동적으로 단일단백질로 정세됨을 확인했다. 이 단백질의 분자량은 약 33000으로서, 분자량 18000과 14000의 subunit로 구성되어 있다. 카드뮴 결합 단백질의 는 19.58이였으며, $100{\mu}{\textrm{g}}$의 단백질 중에 $9.26{\mu}{\textrm{g}}$ 카드뮴을 함유했다. 카드뮴 결합 단백질로부터 14종류의 아미노산이 검출되엇으며, aspartic acid, glycine과 alanine이 비교적 많이 함유되어 있으며, proline, valine 및 methionine은 검출되지 않았다. 본 연구에 사용된 카드뮴 내성효모로부터 분리, 정제된 카드뮴 결합 단백질은 cysteine과 카드뮴을 다량 함유하여 metallothionein의 특징을 잘 나타내고 있었다.

• Journal of Applied Biological Chemistry
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• 제44권3호
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• pp.125-130
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• 2001

A putative protein encoded by Arabidopsis AtMTN3 gene, a homologue of Medicago truncatula MTN3, consists of 285 amino acid residues, and has a predicted molecular mass of 31.5 kDa and a calculated pI of 9.1. Primary amino acid sequence analyses have revealed that the protein contains seven putative transmembrane regions with N-terminus oriented to the outside of the membrane. The AtMTN3 protein shows overall 16.4% of amino acid identity with the rat GALR3 protein, known to be a G-protein-coupled receptor. The gene is present as a single copy in the Arabidopsis genome, and expressed in aerial parts but not in roots of Arabidopsis. Therefore, AtMTN3 appears not to be specifically involved in Rhizobium-induced nodule development, as was predicted for the MTN3 gene. These proteins possibly mediate signal transmission through G-protein-coupled pathways during general interactions between plants and symbiotic or pathogenic microbes.