• 대한치과의사협회지
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• 제10권9호
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• pp.585-586
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• 1972

The demonstration of glycoprotein in developing mandibular bone was observed histochemically, using Clara method and Von Kossa method. The glycoprotein reaction showed slight activity in New bilding bone matrix.

• Journal of Pharmaceutical Investigation
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• 제15권1호
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• pp.1-7
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• 1985

Previous studies show that the free (unbound) fraction of disopyramide in human serum is drug concentration dependent~ at corresponding serum disopyramide concentrations that are achieved clinically. $^1^{\sim}^3^)\;Moreover$, disopyramide free fraction values vary several fold at any given drug concentration in human serum and tend to decrease as serum cocentrations of alpha-I-acid glycoprotein(AAG) incrase.$^4^)$ A recent $study^5^)$ demonstrates that the free fraction of disopyramide inhuman serum increases almost 2-fold following the addition of $14.4{\mu}M/L$ mono-N-dealkyldisopyramide. These studies and others. $^6^),\;^7^)$ prompted the present investigation to characterize the protein binding of disopyramide in human serum and solutions of AAG in the presence of mono-N-dealkyldisopyramide (a major metabolite of, disopyramide) and to determine the utility of using commercially available alpha-I-acid glycoprotein for drug protein binding displacement studies. Because many basic and acidic compounds are known to bind to alpha-I-acid $glycoprotein^8^)$ the present study. was performed to determine whteher commercially available AAG would provide a convenient protein source for such binding studies.

• 한국식품영양과학회지
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• 제28권2호
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• pp.285-291
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• 1999

To confirm the food quality of Urechis unicinctus which have been favored as a special raw seafood in southern area in Korea, the chemical composition of Urechis unicinctus and those glycoprotein were studied. Freeze dried Urechis unicinctus was composed of more than 70% of crude protein and 15% of total carbohydrate. The amino acids such as glycine(18.69%), glutamic acid(12.50%) and aspartic acid(9.37%) were noted as major components of total amino acids. The predominant free amino acids were alanine(32.98%), glycine(27.50%), asparagine(19.65%) and taurine(8.29%), and the sum of them were more than 88% to total free amino acids, so they may cause unique taste of Urechis unicinctus with sweetness. As the basis of sugar composition analysis, 56.35% of glucose and 30.49% of N acetylglucosamine were contained respectively, and they might also play an important role in a sweet taste. The leading carbohydrate moiety of glycoprotein from Urechis unicinctus was identified as glucose and N acetylglucosamine similarly to raw muscle, and they occupied more than 50% of total sugar content. Fucose(18.32%) and D glucuronic acid(12.31%) also detected in higher levels com pared to raw muscle. The total amino acid profile of glycoprotein showed a similar trend to raw muscle protein but glycine was detected a significantly lower than that in raw muscle. The glycoprotein from Urechis unicinctus was composed of 4 kinds of subunits, i.e. 25kDa, 20kDa, 18kDa and 12.5kDa of molecular weights through the SDS polyacrylamide gel electrophoresis. On the basis of the IR spectrum of absorptions appeared in 1,240cm-1 and 850cm-1, the glycoprotein had sulfate groups.

• 공업화학
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• 제24권1호
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• pp.62-66
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• 2013

본 연구는 당근에서 추출한 당근당단백질(carrot glycoprotein, 이하 CG라 명함)의 물리화학적인 특성을 조사하기위하여 수행되었다. 천연 식물성 원료인 당근에서 CG를 제조하여 물리화학적인 특성을 분석하였다. 영양성분 조성을 분석한 결과 CG는 당단백질로서 2.35%의 탄수화물과 94.2%의 단백질로 구성되어있는 것으로 나타났다. 아미노산 조성분석 결과 CG는 콜라겐 펩타이드의 특징인 hydroxyproline과 glycine은 소량 검출되었으며, 포도당과 지방 대사에 관여하는 glutamicacid와 asparticacid가 높게 검출되었다. 또한 열량 분석결과 100 g의 CG는 342.1 kcal의 열량을 지니고 있는 것으로 나타났다. CG의 분자량 분석 결과에서는 594 Da 이하의 평균분자량 분포를 나타내는 특성을 가지고 있는 것을 알 수 있었다.

• 약학회지
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• 제57권4호
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• pp.250-257
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• 2013

Biosimilars are important drugs in medicine and contain many glycosylated proteins. Thorough analysis of the glycosylated protein is a prerequisite for evaluation of biosimilar glycan drugs. A method to assess the diversity of N-glycosylation sites and N-glycans from biosimilar glycan drugs has been developed using two separate methods, LC-MS/MS and MALDI-TOF MS, respectively. Development of sensitive, accurate, and efficient methods for evaluation of glycoproteins is still needed. In this study, analysis of both N-glycosylation sites and N-glycans of glycoprotein was performed using the same LC-MS/MS with two different nano-LC columns, nano-C18 and nano-porous graphitized carbon (nano-PGC) columns. N-glycosylated proteins, including RNAse B (one N-glycosylation site), Fetuin (three sites), and ${\alpha}$-1 acid glycoprotein (four sites), were used, and small amounts of each protein were used for identification of N-glycosylation sites. In addition, high mannose N-glycans (one type of typical glycan structure), Mannose 5 and 9, eluted from RNAse B, were successfully identified using nano-PGC-LC MS/MS analysis, and the abundance of each glycan from the glycoprotein was calculated. This study demonstrated an accurate and efficient method for determination of N-glycosylation sites and N-glycans of glycoproteins based on high sensitive LC-MS/MS using two different nano-columns; this method could be applied for evaluation of the quality of various biosimilar drugs containing N-glycosylation groups.

• International Journal of Industrial Entomology and Biomaterials
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• 제36권1호
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• pp.15-24
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• 2018

N-glycosylation is an important posttranslational modification that results in a variety of biological activities, structural stability, and protein-protein interactions. There are still many mysteries in the structure and function of N-glycans, and detailed elucidation is necessary. Baculovirus expression system (BES) is widely used to produce recombinant glycoproteins, but it is not suitable for clinical use due to differences in N-glycan structure between insects and mammals. It is necessary to develop adequate model glycoproteins for analysis to efficiently alter the insect-type N-glycosylation pathway to human type. The previous research shows the recombinant alpha 1-acid glycoprotein (${\alpha}1AGP$) secreted from silkworm cultured cells or larvae is highly glycosylated and expected to be an excellent research candidate for the glycoprotein analysis expressed by BES. Therefore, we improved the ${\alpha}1AGP$ to be a better model for studying glycosylation. The modified ${\alpha}1AGP$ (${\alpha}1AGP{\Delta}$) recombinant protein was successfully expressed and purified by using BES, however, the expression level in silkworm cultured cells and larvae were lower than that of the ${\alpha}1AGP$. Subsequently, we confirmed the detailed profile of N-glycan on the ${\alpha}1AGP{\Delta}$ by LS/MS analysis the N-glycan structure at each glycosylation site. These results indicated that the recombinant ${\alpha}1AGP{\Delta}$ could be usable as a better model glycoprotein of N-glycosylation research in BES.

• BMB Reports
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• 제32권3호
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• pp.317-319
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• 1999

A leucine aminopeptidase has been isolated from the culture medium of the soil fungus, Aspergillus flavus. The enzyme was found to be a glycoprotein, as judged by electrophoresis analysis and the subsequent staining by the periodic acid-Schiff's reagent. Carbohydrate moieties could be cleaved by N-glycosidase, but not by O-glycosidase, indicating that the glucans are linked to the asparagine residue in the protein. Removal of N-glucans was observed without prior denaturation of the protein, implying that the N-glycosidic linkage is exposed and accessible to glycosidase. When the activity of native or deglycosylated enzyme was measured in the presence of various metal ions, removal of carbohydrates increased the aminopeptidase activity of the enzyme.

• IMMUNE NETWORK
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• 제21권6호
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• pp.39.1-39.18
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• 2021

The high virulent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that emerged in China at the end of 2019 has generated novel coronavirus disease, coronavirus disease 2019 (COVID-19), causing a pandemic worldwide. Every country has made great efforts to struggle against SARS-CoV-2 infection, including massive vaccination, immunological patients' surveillance, and the utilization of convalescence plasma for COVID-19 therapy. These efforts are associated with the attempts to increase the titers of SARS-CoV-2 neutralizing Abs (nAbs) generated either after infection or vaccination that represent the body's immune status. As there is no standard therapy for COVID-19 yet, virus eradication will mainly depend on these nAbs contents in the body. Therefore, serological nAbs neutralization assays become a requirement for researchers and clinicians to measure nAbs titers. Different platforms have been developed to evaluate nAbs titers utilizing various epitopes sources, including neutralization assays based on the live virus, pseudovirus, and neutralization assays utilizing recombinant SARS-CoV-2 S glycoprotein receptor binding site, receptor-binding domain. As a standard neutralization assay, the plaque reduction neutralization test (PRNT) requires isolation and propagation of live pathogenic SARS-CoV-2 virus conducted in a BSL-3 containment. Hence, other surrogate neutralization assays relevant to the PRNT play important alternatives that offer better safety besides facilitating high throughput analyses. This review discusses the current neutralization assay platforms used to evaluate nAbs, their techniques, advantages, and limitations.

• 한국식품저장유통학회지
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• 제21권5호
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• pp.735-739
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• 2014

Newcastle disease virus(NDV) 감염된 baby hamster kidney(BHK) 세포에서 syncytium(합포체) 형성은 세포막 표면으로의 수송된 바이러스 당단백질 hemagglutinin-neuramidase(HN)에 의해 일어난다. HAU 값은 추출물의 농도가 25과 3.2 ug/mL 사이에서는 현저하게 감소하였으나, NDV 감염된 HAD(%)는 25 ug/mL 농도에서 광범위한 흡착능의 감소를 나타내 바이러스 당단백질의 세포내 생합성은 저해되지 않았다. 그러므로, 약용식물인 마황 메탄올 추출물이 바이러스 당단백질의 세포막으로의 수송과 함께 합포체 형성을 저해하여 항바이러스 작용을 하였다. 또한 마황 추출물의 저해활성을 조사한 결과 ${\alpha}$-glucosidase에 대한 추출물의 $IC_{50}$은 $18{\mu}g/mL$이었으며, ${\beta}$-glucosidase, ${\alpha}$-mannosidase, ${\beta}$-mannosidase에 대한 마황 추출물의 $IC_{50}$은 각각 60, 40, $150{\mu}g/mL$로 나타나 ${\beta}$-type glycosidases 보다 ${\alpha}$-type glycosidase에 대한 효소활성 저해능이 우수하였다. 따라서 $IC_{50}$농도에서는 세포내에서 당단백질 생합성은 저해되지 않으며 당단백질의 수송을 저해하는 것으로 판단되었으며 향후 항바이러스 관련 작용기작의 연구가 필요하다고 판단된다.

• 약학회지
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• 제44권2호
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• pp.197-203
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• 2000

The enzymatic properties of $\beta$-galactosidases from Aspergillus oryzae, bovine liver and Saccharomyces pragilis have been studied using enzyme-linked lectin assay based on the RC $A_{120}$ and BS-II lectins which specifically bind to terminal galactose and GlcNAc residue, respectively. Asialofetuin, a monomeric glycoprotein with approximately 48 kDa in molecular weight, was used as a substrate. This glycoprotein contains three N-linked triantennary complex type carbohydrate chains with each of which terminating in Ga1$\beta$P1 longrightarrow4G1cNAc (74%). Their optimal pHs were 3.5 and 6.5 (A. oryzae), and 3.5~5.5 (bovine liver and S. fragilis) at 37$^{\circ}C$ during 24 hrs, and the effective concentrations were 0.9, 2.9, and 1.7 mg/ml, respectively The enzyme from A oryzae requires 100 mM N $a^{+}$ or $K^{+}$, while the enzyme from bovine liver requires $Ba^{2+}$ for activity. However all of the three $\beta$-galactosidases were inactivated by SDS and C $u^{2+}$. These results indicate that the hydrolysis of glycoprotein such as asialofetuin depends on the reaction conditions of $\beta$-galactosidases and some metal ions. ions.