• 전기화학회지
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• 제12권4호
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• pp.329-334
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• 2009

본 연구는 연료전지 운전시 전극 촉매 및 전해질막 내에서 발생하는 연료 및 산화제의 산화/환원 반응 메커니즘, 이동현상, 구성품 열화현상 등을 핵자기 공명 (NMR, Nuclear Magnetic Resonance)을 이용하여 연료전지의 분해나 시료 채취 없이 제자리 (in situ) 분석할 수 있는 진단장치용 연료전지 개발에 관한 것이다. NMR에 사용되는 연료전지는 특수하게 제작된 TCD (Toroid Cavity Detector) 탐침 내부에서 작동하여야 하며, TCD 탐침이 가지는 기하학적 제한 요소들로 인해 일반적인 평판형 연료전지와 달리 원통형으로 제작된다. 이로 인해 반응물의 공급이나 생성물의 제거가 어려우며 누수 현상 및 불균일한 압력 분배가 발생하여 성능이 낮다. 따라서, in situ NMR 분석용 연료전지가 가지는 구조상의 특징인 원통형에 적합한 유로를 설계하고 제작하여 물질 전달 특성을 개선해야 할 필요성이 있다. 본 연구에서는 NMR 장비 내의 자기장에 영향을 미치지 않는 비자성 물질을 이용해 원 통형 공기극 유로를 개발하여, 산소의 공급 및 반응물의 제거를 원활하게 하였다. 또한, 체결 압력을막-전극 접합체에 균일하게 분배하여 누수 및 누액을 차단하였다. 이를 통해, 상온에서 약 $36mW/cm^2$의 우수한 성능을 나타내는 in situ NMR 진단용 직접 메탄올연료전지 시스템을 개발하였다.

• 한국자기공명학회논문지
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• 제23권1호
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• pp.33-39
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• 2019

Studies on the interactions of proteins with partner molecules at the atomic resolution are essential for understanding the biological function of proteins in cells and for developing drug molecules. Solution NMR spectroscopy has shown remarkably useful capability for investigating properties on the weak to strong intermolecular interactions in both diluted and crowded solution such as cell lysates. Of note, the state-of-the-art in-cell NMR method has made it possible to obtain atomistic information on natures of intermolecular interactions between target proteins with partner molecules in living cells. In this mini-review, we comprehensively describe the several technological advances and developments in the in-cell NMR spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.1013-1017
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• 2008

Syndecan-3 is a cell-surface heparan sulfate proteoglycan, which performs a variety of functions during cell adhension process. It is also a coreceptor for growth factor, mediating cell-cell and cell-matrix interaction. Syndecan-3 contains a cytoplasmic domain potentially associated with the cytoskeleton. Syndecan-3 is specifically expressed in neuron cell and has related to neuron cell differentiation and development of actin filament in cell migration. Syndecans each have a unique, central, and variable (V) region in their cytoplasmic domains. And that region of syndecan-3 may modulate the interactions of the conserved C1 regions of the cytoplasmic domains by tyrosine phosphorylation. Cytoplasmic domain of syndecan-3 has been synthesized for NMR structural studies. The solution structure of syndecan-3 cytoplasmic domain has been determined by two-dimensional NMR spectroscopy and simulated-annealing calculation. The cytoplasmic domain of the syndecan proteins has a tendency to form a dimmer conformation with a central cavity, however, that of syndecan-3 demonstrated a monomer conformation with a flexible region near C-terminus. The structural information might add knowledge about the structure-function relationships among syndecan proteins.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.539-542
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• 2001

$^1H$-NMR spectroscopy was used to detect apoptosis in HL-60 cells in vitro. The relationship between cell apoptosis and NMR data was validated by the flow cytometry assay. To evaluate the NMR apoptosis results, the ratio of methylene and methyl groups caused by lipids was used. In addition, an identical analysis was applied to HepG2 cells. Detection of apoptotic cell death by NMR spectroscopy was oserved.

• Journal of Plant Biotechnology
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• 제34권3호
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• pp.207-212
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• 2007

식물현탁배양세포의 whole cell extract의 $^1H$ NMR 스펙트럼 데이터로부터 통계분석기법을 활용하여 GABA의 간단하고 신속한 정량분석방법을 확립하였다. 이 기술을 활용하여 고등식물 8종의 9개 세포주를 MS 배지에 1 mg/L의 2,4-D를 첨가한 배지에 유지하였을 때 고수 (Coriandrum sativum L.)가 가장 많은 양의 GABA를 생산하였다. 고수 현탁배양세포로부터 2,4-D농도 및 배양기간에 따른 GABA의 생산성 변화를 조사한 결과 현탁배양세포를 0.5 mg/L 2,4-D가 첨가된 배지에서 3주간 배양된 현탁배양세포를 이용할 경우 GABA 함량이 건중량 1 g 당 16.9 mg으로 가장 높게 생산되었다. 본 연구에서 확립된 간단하고 신속한 분석법으로 다양한 식물자원으로부터 GABA의 생산성을 초고속탐색(high-throughput screenig)할 수 있을 것이며 고수 현탁세포배양법으로 GABA의 상업적 대량생산이 가능할 것으로 전망된다.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.83-87
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• 2015

Syndesmos, which is co-localized with syndecan-4 cytoplasmic domain ($Syn4^{cyto}$) in focal contacts, interacts with various cell adhesion adaptor proteins including $Syn4^{cyto}$ to control cell signaling. Syndesmos consists of 211 amino acids and it exists as a dimer (44kDa) in solution. Recently, we have determined the structure of syndesmos by x-ray crystallography, however, dynamics related to syndecan binding still remain elusive. In this report, we performed NMR experiments to acquire biochemical and structural information of syndesmos. Based on a series of three-dimensional triple resonance experiments on a $^{13}C/^{15}N/^2H$ labeled protein, NMR spectra were obtained with well dispersed and homogeneous NMR data. We present the sequence specific backbone assignment of syndesmos and assigned NMR data with combination structural information can be directly used for the studies on interaction with $Syn4^{cyto}$ and other binding molecules.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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• pp.90-90
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• 2002

Syndecans, transmembrane heparan sulfate proteoglycans, are coreceptors with integrin in cell adhesion process. It forms a ternary signaling complex with protein kinase C and phosphatidylinositol 4,5 bisphosphate (PIP2) for integrin signaling. NMR data indicates that cytoplasmic domain of syndecan-4 (4L) undergoes a conformational transition in the presence of PIP2, forming oligomeric conformation. The structure based on NMR data demonstrated that syndecan-4L itself forms a compact intertwined symmetric dimer with an unusual clamp shape for residues Leu$^{186}$ -Ala$^{195}$ . The molecular surface of the syndecan-4L dimer is highly positively charged. In addition, no inter-subunit NOEs in membrane proximal amino acid resides (Cl region) has been observed, demonstrating that the Cl region is mostly unstructured in syndecan-4L dimmer. However, the complex structure in the presence of PIP2 induced a high order multimeric conformation in solution. In addition, phosphorylation of cytoplasmic domain induces conformational change of syndecan-4, resulting inhibition of PKC signaling. The NMR structural data strongly suggest that PIP2 promotes oligomerization of syndecan-4 cytoplasmic domain for PKC activation and further induces structural reorganization of syndecan for mediating signaling network in cell adhesion procedure.

• Journal of Microbiology
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• 제33권4호
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• pp.328-333
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• 1995

$\^$31/ P-NMR experiment was performed to detect phophonates (Pn) utilization and degradation in the several different C-P lyase mutants of E. coli and in E. aerogenes and the recombinants. The relative peak intensity (RPI) for the standard samples of 0.5 mM methylphosphonate (MPn) and 1.0 mM aminoethylphosphonate in glucose-MOPS medium showed 0.5 : 1.0 ratio. In the case of BW14329 (.DELTA.phnC-P, .delta.phoA), RPI did not change significantly after 24 hrs culturing, which means it nearly could not utilize Pn. In vivo $\^$31/ P-NMR spectrum of E. aerogens (BWKL 16627) during 3 hrs starvation showed two intense peaks at 0-2 ppm and at near-10 ppm which indicate intracellular orthophosphate (Pi) and pyrophosphate (PPi), respectively. Both of them might be released by degradation of inorganic polyphosphate pool. When MPn is supplied to the medium as an unique P source, Pi content in the cell has the constant, but PPi seems to be slightly decreased. Recombinants (BWKL 16954) grew slower than E. aerogenes in the glucose-MOPS media with various P sources. In vivo $\^$31/ P-NMR spectrum of recombinant did not show any intense signal in the cell. Surprisingly, under the cultivation adding with MPn, a few intense peaks in the region of Pi AND phospate monoester were detected.

• 한국자기공명학회논문지
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• 제24권3호
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• pp.77-85
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• 2020

Stable isotope enrichment in proteins is necessary for high-resolution nuclear magnetic resonance (NMR) experiments. Although methods for ¹³C, ¹⁵N and ²H-enrichment in prokaryotic cells are well established, full processing and correct folding of complex protein systems require higher organisms as the expression host. In the present study, we review recent efforts to enrich stable isotopes in mammalian cells for protein NMR studies.

• Journal of Plant Biotechnology
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• 제33권4호
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• pp.283-288
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• 2006

건조된 벼 5 품종의 whole cell extracts로부터 $^1H$ NMR 스펙트럼 조사를 통해 다변량 통계분석법을 활용하여 벼 종자의 품종 구분이 가능함을 조사하였다. $^1H$ NMR스펙트럼 데이터에 기초한 PCA분석 결과 크게 3개의 그룹으로 구분이 이루어졌다. 즉, 상주벼가 나머지 4 품종의 벼와 크게 다르게 구분이 이루어졌으며 동진벼와 심백벼, 그리고 화만벼와 심백hetero 품종이 각각 하나의 소그룹으로 구분이 이루어졌다. 스펙트럼 영역에 있어서는 carbohydrate region이 품종에 따라 크게 달라지는 것으로 보아 탄수화물의 정량정성적 차이가 metabolic profiting에 의한 품종 구분에 중요한 역할을 하는 것으로 추론된다. 또한 $^1H$ NMR 스펙트럼 데이터에 기초하여 주요 당 화합물 (sucrose, glucose, maltose 등)의 상대적인 정량분석을 조사한 결과 상주벼의 경우 다른 벼 품종에 비해 sucrose 및 glucose 함량은 큰 차이가 없었으나 maltose 함량이 타 품종에 비해 약 2-4배 높음을 알 수 있었다. 따라서 본 연구에서 확립한 벼 종자의 whole cell extracts로부터 $^1H$ NMR 스펙트럼을 이용한 metabolic profiling 방법은 다양한 벼 종자의 신속한 품종구분은 물론 주요 carbohydrates의 간편한 정량분석 체계로 활용이 가능할 것으로 예상된다.