• Title/Summary/Keyword: molecular functions

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Preliminary Molecular Dynamics Simulations of the OSS2 Model for the Solvated Proton in Water

  • Lee, Song Hui
    • Bulletin of the Korean Chemical Society
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    • v.22 no.8
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    • pp.847-849
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    • 2001
  • The OSS2(Ojame-Shavitt-Singer 2)[L. Ojame et al., J. Chem. Phys. 109, 5547 (1998)] model as a dissociable water model is examined in order to study the dynamics of H+ in water. MD simulations for 216 water system, 215 water + H+ ion system, and 215 water + OH- ion system using the OSS2 model at 298.15 K with the use of Ewald summation are carried out. The calculated O-H radial distribution functions for these systems are essentially the same and are in very good agreement with that obtained by Ojame.

Crosstalk between integrin and receptor tyrosine kinase signaling in breast carcinoma progression

  • Soung, Young-Hwa;Clifford, John L.;Chung, Jun
    • BMB Reports
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    • v.43 no.5
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    • pp.311-318
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    • 2010
  • This review explored the mechanism of breast carcinoma progression by focusing on integrins and receptor tyrosine kinases (or growth factor receptors). While the primary role of integrins was previously thought to be solely as mediators of adhesive interactions between cells and extracellular matrices, it is now believed that integrins also regulate signaling pathways that control cancer cell growth, survival, and invasion. A large body of evidence suggests that the cooperation between integrin and receptor tyrosine kinase signaling regulates certain signaling functions that are important for cancer progression. Recent developments on the crosstalk between integrins and receptor tyrosine kinases, and its implication in mammary tumor progression, are discussed.

In vitro Constructive Approaches to the Origin of Coding Sequences

  • Shiba, Kiyotaka
    • BMB Reports
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    • v.31 no.3
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    • pp.209-220
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    • 1998
  • How did nature create the first set of genes at the beginning of life on Earth? One of the goals of molecular biology is to elucidate the fundamental rules governing how genes and, therefore, proteins were created. Through experiments carried out in the emerging field of "in vitro" or "benchtop" evolution studies, we are gaining new insights into the origins of genes and proteins as well as the origins of their functions (e.g., catalysis). In this review, I present an overview of recent experimental approaches to the question of the origin and evolution of genes. In addition, I will introduce a novel in vitro protein emergence system that was recently developed in my laboratory.

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Molecular Dynamics Study on Property Change of CMP Process by Pad Hardness (CMP 공정에서 연마패드 경도에 따른 연마 특성 변화 분자동력학 연구)

  • Kwon, Oh Kuen;Choi, Tae Ho;Lee, Jun Ha
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.1
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    • pp.61-65
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    • 2013
  • We investigated the wearable dynamics of diamond spherical abrasive during the substrate surface polishing under the pad compression via classical molecular dynamics modeling. We performed three-dimensional molecular dynamics simulations using the Morse potential functions for the copper substrate and the Tersoff potential function for the diamond abrasive. The pad hardness had a big impact on the wearable dynamics of the abrasive. The moving speed of the abrasive decreased with increasing hardness of the pad. As the hardness decreased, the abrasive was indented into the pad and then the sliding motion of the abrasive was increased. So the pad hardness was greatly influenced on the slide-to-roll ratio as well as the wearable rate.

Molecular Characterization of Survival and Toxigenesis of Vibrio vulnificus

  • Choi Sang Ho
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2002.10a
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    • pp.56-58
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    • 2002
  • Understanding the molecular pathogenesis of the multifaceted host-pathogen interaction is critical in the development of improved treatment and prevention, as well as elucidating how certain bacteria can circumvent host defenses, multiply in the host, and cause such extensive damage. Disease caused by infection with V. vulnificus is remarkable for the invasive nature of the infection, ensuing severe tissue damage, and rapidly fulminating course. The characterization of somatic as well as secreted products of V. vulnificus has yielded a large list of putative virulence attributes, whose known functions are easily imagined to explain the pathology of disease. These putative virulence factors include a carbohydrate capsule, lipopolysaccharide, a cytolysin/hemolysin, elastolytic metalloprotease, iron sequestering systems, lipase, and pili. However, only few among the putative virulence factors has been confirmed to be essential for virulence by the use of molecular Koch's postulates. This presentation describes molecular biological characterization of the virulence factors contributing to survival as well as to toxigenesis of V. vulnificus.

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Disruption of ATP binding destabilizes NPM/B23 and inhibits anti-apoptotic function

  • Choi, Joung-Woo;Lee, Sang-Bae;Ahn, Jee-Yin;Lee, Kyung-Hoon
    • BMB Reports
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    • v.41 no.12
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    • pp.840-845
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    • 2008
  • Nucleophosmin/B23, a major nucleolar phosphoprotein, is overexpressed in actively proliferating cells. In this study, we demonstrate that B23 exclusively localizes in the nucleolus, whereas ATP depletion results in the redistribution of B23 throughout the whole nucleus and destabilizes B23 via caspase-3 mediated cleavage. Interestingly, ATP binding precedes PI(3,4,5)P3 binding at lysine 263 and ATP binding mutants fail to restore the anti-apoptotic functions of B23 in PC12 cells. Thus, the ATP-B23 interaction is required for the stability of the B23 protein and regulates cell survival, confining B23 within the nucleolus in PC12 cells.

Structure, signaling and the drug discovery of the Ras oncogene protein

  • Han, Chang Woo;Jeong, Mi Suk;Jang, Se Bok
    • BMB Reports
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    • v.50 no.7
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    • pp.355-360
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    • 2017
  • Mutations in Ras GTPase are among the most common genetic alterations in human cancers. Despite extensive research investigating Ras proteins, their functions still remain a challenge over a long period of time. The currently available data suggests that solving the outstanding issues regarding Ras could lead to development of effective drugs that could have a significant impact on cancer treatment. Developing a better understanding of their biochemical properties or modes of action, along with improvements in their pharmacologic profiles, clinical design and scheduling will enable the development of more effective therapies.

A Study on Nanoscale Surface Polishing using Molecular Dynamics Simulations (분자동역학 시뮬레이션을 이용한 나노스케일 표면 절삭에 관한 연구)

  • Kang, Jeong-Won;Choi, Young-Gyu
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.3
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    • pp.49-52
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    • 2011
  • This paper shows the results of classical molecular dynamics modeling for the interaction between spherical nano abrasive and substrate in chemical mechanical polishing processes. Atomistic modeling was achieved from 3-dimensional molecular dynamics simulations using the Morse potential functions for chemical mechanical polishing. The abrasive dynamics was modeled by three cases, such as slipping, rolling, and rotating. Simulation results showed that the different dynamics of the abrasive results the different features of surfaces. The simulation concerning polishing pad, abrasive particles and the substrate has same results.

Mitochondrial Targeting Domain Homologs Induce Necrotic Cell Death Via Mitochondrial and Endoplasmic Reticulum Disruption

  • Park, Junghee;Han, Ji-Hye;Myung, Seung-Hyun;Chung, Hea-jong;Park, Jae-il;Cho, Ju-Yeon;Kim, Tae-Hyoung
    • Journal of Microbiology and Biotechnology
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    • v.31 no.6
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    • pp.875-881
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    • 2021
  • The mitochondrial targeting domain (MTD) of Noxa contributes to its mitochondrial localization and to apoptosis induction. As a peptide, MTD fused with octa-arginine (R8), a CPP, induces necrosis related to intracellular calcium influx and destruction of mitochondria and endoplasmic reticulum. We searched for homologs of MTD, and compared their cell killing capability when fused with R8. Three of the seven peptides triggered cell death with similar mechanisms. The comparative analysis of peptide sequences showed that four amino acid sites of MTD are critical in regulating necrosis, suggesting the potential to generate artificial, adjustable cytotoxic peptides, which could be effective medicines for many diseases. Thus, homologs functionality could hint to the functions of their belonging proteins.