• 정보처리학회지
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• 제15권2호
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• pp.113-122
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• 2008

• KSBB Journal
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• 제30권5호
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• pp.230-238
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• 2015

Abnormal glycosylation can significantly affect the intrinsic functions (i.e., stability and solubility) of proteins and the extrinsic protein interactions with other biomolecules. For example, recombinant glycoprotein therapeutics needs proper glycosylation for optimal drug efficacy. Therefore, there has been a strong demand for rapid, sensitive and high-through-put glycomics tools for real-time monitoring and fast validation of the biotherapeutics glycosylation. Although liquid chromatography tandem mass spectrometry (LC-MS/MS) is one of the most powerful tools for the characterization of glycan structures, it is generally time consuming and requires highly skilled personnel to collect the data and analyze the results. Recently, as an alternative method, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS), which is a fast, robust and easy-to-use instrumentation, has been used for quantitative glycomics with various chemical derivatization techniques. In this review, we highlight the recent advances in MALDI-MS based quantitative glycan analysis according to the chemical derivatization strategies. Moreover, we address the application of MALDI-MS for high-throughput glycan analysis in many fields of clinical and biochemical engineering.

• 한국식품과학회지
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• 제37권6호
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• pp.898-904
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• 2005

본 연구는 화살나무의 줄기와 날개를 열수 추출하여 분자량 크기별로 네 분획(F I. F II, F III, F IV)으로 분리하여 각 분획물의 성분조성을 분석하였고, 이들 각 분획물의 생리활성을 알아보기 위해 DPPH를 이용한 유리 라디칼 소거능과 동물 세포에서 활성산소종 제거능에 대하여 조사하였다. 열수 추출물의 정성반응 결과, 네 분획물 모두 대부분 탄수화물이었고, 소량의 단백질을 함유하였으며, 일부 분획물에는 소량의 페놀 화합물 및 유기산이 함유되어 있었다. 주요 구성 성분인 총당과 총단백질 함량은 448mg/g과 21mg/g이었으며, 총 당의 함량은 F III가 가장 높았고, F IV, F II 및 F I의 순서였다. 네 분획물을 가수분해하여 이들의 구성당을 분석한 결과, 중성당은 mannose : fucose : galactose : glucose가 0.01 : 0.02 : 0.14 : 0.83의 비율로, 아미노당은 galactosamine : glucosamine이 0.01 : 0.99의 비율로 구성되어 있었으며, 전체 구성당 함량에서 중성당 : 아미노당의 비율은 0.94 : 0.04로 조성된 다당체였다. 분획물별로 총단백질과 구성 아미노산은 F IV가 가장 높았으며, F III, F II 및 F I의 순서로 함유하였다. 조 추출물에 함유된 아미노산의 종류와 양은 Glu>Asp>Pro>Gly>Leu>Val>Ser>Ala>Thr>Ile>Phe>Cys>His>Arg>Met>Lys>Try>Trp>Cys2의 순서로 19종의 아미노산이 분석되었으며, 특히 산성 아미노산과 중성 아미노산 함량이 높았다. 네 분획물을 각 농도별로 처리하여 DPPH 유리 라디칼 소거능을 조사한 결과는 $50-1,000{\mu}g/mL$ 처리했을 때 농도에 비례하여 네 분획물 모두에서 F IV, F III, F II 및 F I의 순서로 활성을 나타냈다. CHO-k1 동물 세포에서 활성산소종 제거능을 조사한 결과는, 분획물을 $1-100{\mu}g/mL$까지 처리한 농도에 비례하여 활성이 상승되는 것으로 나타났으나 $100{\mu}/mL$ 이상의 처리농도에서는 거의 변화를 보이지 않았다. 각 분획물별로 F IV이 가장 높은 활성을 보였으며, 그 다음 F III, F I이었으며, F II은 가장 낮은 활성을 나타냈다. 화살나무 열수 추출물 중에는 항산화능과 활성산소종 제거능을 나타내는 물질이 여러 가지 있을 것으로 추정되지만 분자량 크기별로 분획한 네 분획물의 정색반응과 성분조성을 조사한 결과, 주요 구성성분은 단백질이 결합되어 있을 가능성이 높으며, DPPH 유리 라디칼 소거능과 CHO-k1의 세포에서 활성산소종 제거능의 생리활성을 나타내는 다당체(bioactive carbohydrate)일 것으로 사료된다.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.437-442
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• 2013

A new series of 4-(2-(substituted)pyridin-4-yl)-3-(3-methoxy-5-methylphenyl)-1H-pyrazoles (4a-f) and their 1,2-isoxazole analogues (5a-f) has been rationally designed, synthesized and screened against both ROS and MAPK14 kinases. Compounds 4b, 4c and 4e showed moderate inhibitions against both ROS and MAPK14 kinases. Compound 4e has showed the strongest inhibitions with IC50 values of 1.25 ${\mu}M$ and 3.00 ${\mu}M$ against ROS and MAPK14 kinases, respectively. A brief structure-activity relationship study and a molecular modeling study were made revealing a group of essential structural features for good kinase inhibitory activity within this new class of kinase inhibitors.

• Mass Spectrometry Letters
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• 제6권3호
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• pp.53-58
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• 2015

Recombinant erythropoietins (EPOs) are an important class of biotherapeutics that stimulate red blood cell production. The quality, safety, and potency of EPO variants are determined largely by their glycosylation, which makes up nearly half their mass. Thus, detailed glycomic analyses are important to assess biotherapeutic quality and establish the equivalency of biosimilar EPOs now coming to market. High-resolution mass spectrometry (MS) has recently emerged as the premier tool for glycan analysis in EPOs. Using the accurate mass measurements provided by high-resolution MS, the compositions of even large, complex glycans can easily be determined. When combined with a nano-LC separation, differentiation of structural isomers also becomes a possibility. These components, together, provide a comprehensive picture of biotherapeutic glycosylation. In this review, we provide an overview of MS-based analytical platform for glycomic characterization of EPO biotherapeutics and biosimilars.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3629-3634
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• 2012

A series of new 4-(pyridin-4-yl)-(3-methoxy-5-methylphenyl)-1H-pyrazoles (6a-k & 7a-l) has been rationally designed based on the structure of the lead compound KIST301080, a selective ROS receptor tyrosine kinase inhibitor, in order to study the activity of ROS of this new class of inhibitors. The compounds were synthesized and screened against ROS kinase, where compound 6h showed moderate inhibitory activity with an $IC_{50}$ value of $6.25{\mu}M$. The study emphasized the importance of the acetonitrile group at the pyrazole ring and also the importance of having a hydrogen bond donor on the distal phenyl ring linked to the pyridine moiety.

• BMB Reports
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• 제40권4호
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• pp.539-546
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• 2007

The lysozymes encoded by bacteriophage T7 and K11 are both bifunctional enzymes sharing an extensive sequence homology (75%). The constructions of chimeric lysozymes were carried out by swapping the N-terminal and C-terminal domains between phage T7 and K11 lysozymes. This technique generated two chimeras, T7K11-lysozyme (N-terminal T7 domain and C-terminal K11 domain) and K11T7-lysozyme (N-terminal K11 domain and C-terminal T7 domain), which are both enzymatically active. The amidase activity of T7K11-lysozyme is comparable with the parental enzymes while K11T7-lysozyme exhibits an activity that is approximately 45% greater than the wild-type lysozymes. Moreover, these chimeric constructs have optimum pH of 7.2-7.4 similar to the parental lysozymes but exhibit greater thermal stabilities. On the other hand, the chimeras inhibit transcription comparable with the parental lysozymes depending on the source of their N-terminals. Taken together, our results indicated that domain swapping technique localizes the N-terminal region as the domain responsible for the transcription inhibition specificity of the wild type T7 and K11 lysozymes. Furthermore, we were able to develop a simple and rapid purification scheme in purifying both the wild-type and chimeric lysozymes.

• 대한의생명과학회지
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• 제12권1호
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• pp.9-16
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• 2006

We investigated the effects of 835-MHz electromagnetic field (EMF), one of the most popular communication frequency band in Korean code-division multiple-access (CDMA) mobile phone system, on cellular signal transduction. For this, we examined the change of intracellular calcium $([Ca^{2+}]_i)$, reactive oxygen species (ROS) and F-actin polymerization after exposure to 835-MHz EMF followed by the treatment of agonists in Rat-2 fibroblast cells. Culture cells were pretreated with serum-tree medium and concomitantly exposed to 835-MHz at specific absorption rate (SAR) of 4.0 W/kg for 24 hr in a specialized designed apparatus based on Transverse Electro Magnetics (TEM) wave theory. Intracellular $Ca^{2+}$ responses to lysophosphatidic acid (LPA) and epidermal growth factor (EGF) in Rat-2 fibroblast after exposure to 835-MHz EMF were shown to be similar pattern as observed in normal cultured cells. However, the LPA-induced calcium spiking was slightly delayed to 7 sec and sustained thereafter to a little higher ground level under 835-MHz EMF radiation compared to unexposed cells. ROS production level by LPA in the exposed cells was not different from that in control. Furthermore, LPA induced the production of stress fibers with no significant difference in the exposed and unexposed cells. These results suggest that mobile phone radiation (835-MHz, SAR 4.0 W/kg) may not be directly related to signal transduction in Rat-2 fibroblasts except the slight effect of calcium spiking in LPA-induced cells but remain to be further elucidated for possible indirect intervention.

• Plant Biotechnology Reports
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• 제2권2호
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• pp.113-122
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• 2008

Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.