• Molecules and Cells
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• v.24 no.1
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• pp.27-36
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• 2007

The hypothetical protein TTC0263 of Thermus thermophilus HB27 is a thermophilic tetratricopeptide repeat (TPR)-containing protein. In the present study, the TPR region (residues 26-230) was resolved at $2.5{\AA}$ with R-factors of $R/R_{free}$ = 23.6%/28.6% $R/R_{free}=23.6%/28.6%$. TTC0263 consists of 11 helices that form five TPR units. Uniquely, it contains one atypical "extended" TPR (eTPR) unit. This comprises extended helical residues near the loop region of TTC0263, such that the helical length of eTPR is longer than that of the canonical TPR sequence. In addition, the hybrid TPR domain of TTC0263 possesses oligomer-forming characteristics. TPR domains are generally involved in forming multi-subunit complexes by interacting with each other or with other subunit proteins. The dynamic structure of TTC0263 described here goes some way to explaining how TPR domains mediate the formation of multi-subunit complexes.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.913-916
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• 1999

Recent developments of carbon nanotubes are reviewed［1,2,3,4］. We use Tersoff carbon potential for bonded interactions［5］ and Lennard-Jones 12-6 potential for non bonding interactions［6］to describe mechanical properties of the temperature-dependent armchair single wall carbon nanotube. At first we report that through defect number and bonding energy calculation, how single wall carbon nanutube is capped in the constant temperature. (300K, 2000K, 3000K, 4000K) At second, we perform MD simulation, which are performed on the energy optimized structure of carbon nanotube.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.3
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• pp.124-131
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• 2015

Hyperpolarization methods are the most emerging techniques in the field of magnetic resonance (MR) researches since they make a contribution to overcoming sensitivity limitation of MR spectroscopy and imaging, leading to new fields of researches, real-time in vivo metabolic/molecular imaging and MR analysis of chemical/biological reactions in non-equilibrium conditions. Make use of enormous signal enrichments, it becomes feasible to investigate various chemical and biochemical systems with low ${\gamma}$ nuclei in real-time. This review deals with the theoretical principals of common hyperpolarization methods and their experimental features. In addition, more detailed theories, mechanisms, and applications of dissolution dynamic nuclear polarization (D-DNP) are discussed.

• BMB Reports
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• v.49 no.9
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• pp.459-473
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• 2016

Neurodegenerative diseases (NDs) often involve the formation of abnormal and toxic protein aggregates, which are thought to be the primary factor in ND occurrence and progression. Aged neurons exhibit marked increases in aggregated protein levels, which can lead to increased cell death in specific brain regions. As no specific drugs/therapies for treating the symptoms or/and progression of NDs are available, obtaining a complete understanding of the mechanism underlying the formation of protein aggregates is needed for designing a novel and efficient removal strategy. Intracellular proteolysis generally involves either the lysosomal or ubiquitin-proteasome system. In this review, we focus on the structure and assembly of the proteasome, proteasome-mediated protein degradation, and the multiple dynamic regulatory mechanisms governing proteasome activity. We also discuss the plausibility of the correlation between changes in proteasome activity and the occurrence of NDs.

• Molecules and Cells
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• v.39 no.12
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• pp.841-846
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• 2016

Local protein synthesis mediates precise spatio-temporal regulation of gene expression for neuronal functions such as long-term plasticity, axon guidance and regeneration. To reveal the underlying mechanisms of local translation, it is crucial to understand mRNA transport, localization and translation in live neurons. Among various techniques for mRNA analysis, fluorescence microscopy has been widely used as the most direct method to study localization of mRNA. Live-cell imaging of single RNA molecules is particularly advantageous to dissect the highly heterogeneous and dynamic nature of messenger ribonucleoprotein (mRNP) complexes in neurons. Here, we review recent advances in the study of mRNA localization and translation in live neurons using novel techniques for single-RNA imaging.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.130-130
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• 2012

Axial bindings of diatomic molecules to metalloporphyrins involve in the dynamic processes of biological functions such as respiration, neurotransmission, and photosynthesis. The binding reactions are also useful in sensor applications and in control of molecular spins in metalloporphyrins for spintronic applications. Here, we present the binding structures of diatomic molecules to surface- supported Co-porphyrins studied using scanning tunneling microscopy. Upon gasexposure, three-lobed structures of Co-porphyrins transformed to bright ring shapes on Au(111), whereas H2-porphyrins of dark rings remained intact. The bright rings are explained by the structures of reaction complexes where a diatomic ligand, tilted away from the axis normal to the porphyrin plane, is under precession. Our results are consistent with previous bulk experiments using X-ray diffraction and nuclear magnetic resonance spectroscopy.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.141-155
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• 2014

Peptide bond hydrolysis는 세포 내외의 생화학반응에 있어서 핵심이다. 하지만 amide Hydrolysis Mechanism은 아직 명확하게 규명되지 않았다. pH가 중성인 물에서의 비 촉매 가수분해가 발생하는 몇몇 실험적 증거가 있지만, 해당 반응 매커니즘은 4 가지(non-assisted concerted, non-assisted step-wise, assisted concerted, assisted step-wise)로 여전히 논란이 있다. 이번 연구에서는, Formamide의 가능한 Hydrolysis Mechanism을 자세히 연구해보고자 한다. 먼저, Ab-initio 계산을 통해 4가지 반응 메커니즘의 다시 한번 확인하고, quantum chemical calculations과 quantum mechanical molecular dynamic이 결합된 (QMMD) simulation을 통하여 water solvent에서의 반응 메커니즘의 에너지관계를 규명하였다. 결론적으로 아직 계산이 끝나지 않은 supported concerted mechanism을 제외한 모든 계산에서 non-supported, supported 두 system 모두에서 step-wise가 일어나기 쉬웠고, non-supported 보다 supported mechanism이 선호됨을 보였다. Intermediate인 amino-gem-diol의 수용액 상에서 안정화 또한 나타났다. 이는 Ab-initio 계산만 통해서는 정확하게 산출할 수 없는 엔트로피의 영향을 잘 보여준다.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.433-435
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• 2005

We have studied the realigning behavior of liquid crystal molecules in liquid crystalline polymer/liquid crystal(LCP/LC) system when they are exposed to external stimulation such as bending and pressing. The birefringence of the LCP/LC in a flexible display device was measured as a function of bending or pressing deformation. The microscopic dynamic behavior of main chain, side chain, and the LC were characterized by FTIR and polarization optical microscopy. When the device is deformed in scattering memory state, liquid crystal(LC) director is found to align from randomly oriented domain state(scattering state) to homeotropic state.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.197-203
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• 2003

The purpose of the study is to develop an integrated knowledge structuring system for the domain of engineering, in which ontology-based literature mining, knowledge acquisition, knowledge integration, and knowledge retrieval are combined using XML-based tag information and ontology management. The system supports combining different types of databases (papers and patents, technologies and innovations) and retrieving different types of knowledge simultaneously. The main objective of the system is to facilitate knowledge acquisition and knowledge retrieval from documents through an ontology-based dynamic similarity calculation and a visualization of automatically structured knowledge. Through experimentations we conducted using 100,000 words economic documents reported in the "Go！ Japan" project for analyzing Japanese industrial situation, and 100,000 words molecular biology Papers, we show the system is Practical enough for accelerating knowledge acquisition and knowledge discovery from the information sea.

• BMB Reports
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• v.51 no.3
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• pp.157-162
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• 2018

Angiogenesis is a complex, multistep process involving dynamic changes in endothelial cell (EC) shapes and behaviors, especially in specialized cell types such as tip cells (with active filopodial extensions), stalk cells (with less motility) and phalanx cells (with stable junction connections). The Hippo-Yes-associated protein (YAP)/ transcription activator with PDZ binding motif (TAZ) signaling plays a critical role in development, regeneration and organ size by regulating cell-cell contact and actin cytoskeleton dynamics. Recently, with the finding that YAP is expressed in the front edge of the developing retinal vessels, Hippo-YAP/TAZ signaling has emerged as a new pathway for blood vessel development. Intriguingly, the LATS1/2-mediated angiomotin (AMOT) family and YAP/TAZ activities contribute to EC shapes and behaviors by spatiotemporally modulating actin cytoskeleton dynamics and EC junction stability. Herein, we summarize the recent understanding of the role of Hippo-YAP/TAZ signaling in the processes of EC sprouting and junction maturation in angiogenesis.