• Title/Summary/Keyword: Small molecule

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Enhanced Chemical Shift Analysis for Secondary Structure prediction of protein

  • Kim, Won-Je;Rhee, Jin-Kyu;Yi, Jong-Jae;Lee, Bong-Jin;Son, Woo Sung
    • Journal of the Korean Magnetic Resonance Society
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    • v.18 no.1
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    • pp.36-40
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    • 2014
  • Predicting secondary structure of protein through assigned backbone chemical shifts has been used widely because of its convenience and flexibility. In spite of its usefulness, chemical shift based analysis has some defects including isotopic shifts and solvent interaction. Here, it is shown that corrected chemical shift analysis for secondary structure of protein. It is included chemical shift correction through consideration of deuterium isotopic effect and calculate chemical shift index using probability-based methods. Enhanced method was applied successfully to one of the proteins from Mycobacterium tuberculosis. It is suggested that correction of chemical shift analysis could increase accuracy of secondary structure prediction of protein and small molecule in solution.

Understanding EGFR Signaling in Breast Cancer and Breast Cancer Stem Cells: Overexpression and Therapeutic Implications

  • Alanazi, Ibrahim O;Khan, Zahid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.445-453
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    • 2016
  • Epidermal growth factor receptors (EGFRs/HERs) and downstream signaling pathways have been implicated in the pathogenesis of several malignancies including breast cancer and its resistance to treatment with chemotherapeutic drugs. Consequently, several monoclonal antibodies as well as small molecule inhibitors targeting these pathways have emerged as therapeutic tools in the recent past. However, studies have shown that utilizing these molecules in combination with chemotherapy has yielded only limited success. This review describes the current understanding of EGFRs/HERs and associated signaling pathways in relation to development of breast cancer and responses to various cancer treatments in the hope of pointing to improved prevention, diagnosis and treatment. Also, we review the role of breast cancer stem cells (BCSCs) in disease and the potential to target these cells.

Identification of a Novel Small Molecule Inhibitor Against SARS Coronavirus Helicase

  • Cho, Jin-Beom;Lee, Jin-Moo;Ahn, Hee-Chul;Jeong, Yong-Joo
    • Journal of Microbiology and Biotechnology
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    • v.25 no.12
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    • pp.2007-2010
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    • 2015
  • A new chemical inhibitor against severe acute respiratory syndrome (SARS) coronavirus helicase, 7-ethyl-8-mercapto-3-methyl-3,7-dihydro-1H-purine-2,6-dione, was identified. We investigated the inhibitory effect of the compound by conducting colorimetry-based ATP hydrolysis assay and fluorescence resonance energy transfer-based double-stranded DNA unwinding assay. The compound suppressed both ATP hydrolysis and double-stranded DNA unwinding activities of helicase with IC50 values of 8.66 ± 0.26 μM and 41.6 ± 2.3 μM, respectively. Moreover, we observed that the compound did not show cytotoxicity up to 80 μM concentration. Our results suggest that the compound might serve as a SARS coronavirus inhibitor.

Structural Requirement of Isoflavonones for the Inhibitory Activity of Interleukin-5

  • Cho, Soo-Hyun;Lee, Jee-Hyun;Dang, The-Hung;Ju, Jung-Hun;Kim, Mi-Kyung;Lee, Seung-Ho;Ryu, Jae-Chun;Kim, Young-Soo;Jung, Sang-Hun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.354.3-355
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    • 2002
  • Interleukin (IL)-5 appears to be one of the main proinflammatory mediators among a growing number of cytokines and chemokines that induce eosinophilic inflammation. Sophoricoside and their analogs isolated from Sophora japonica show relatively potent inhibitory activity of interleukin (IL)-5 as a small molecule. To identify structural requirements of this isoflavonone for its inhibitory activity against IL -5. isoflavonones. isoflavanones, and their glycosides were prepared and tested their inhibitory activity against IL-5. (omitted)

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Synthesis of Host Polymers and Guests for Electrophosphorescence

  • Holmes Andrew B.;Chan, Khai-Leok;Cho, Sung-Yong;Evans Nicholas R.;Grimsdale Andrew C.;Mak Chris S.K.;Sandee Albertus J.;Watkins Scott E.;Williams Charlotte K.
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.21-22
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    • 2006
  • Significant progress has been realized in the design and synthesis of light emitting polymers with emission over the whole range of the visible spectrum. However up to seventy-five percent of charge recombination events can lead to triplet states that decay non-radiatively. Following the pioneering work in the field of small molecule organic light emitting devices it has been found that solution processible iridium polymer complexes can be used to harness the wasted triplet energy. In this paper new results concerning electrophosphorescence of solution processible tethered iridium polymer derivatives will be presented. Furthermore our approaches to the design of new high triplet energy conjugated polymer hosts will be reported.

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Revesible Switching between Nematic Gel and Isotriopic Fluid Triggered by External Stimuli in Aqueous Self-Assembly of Supramolecular Nanocylinders

  • Ryu, Ja-Hyoung;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.308-308
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    • 2006
  • We have demonstrated that the cylindrical micelles self-assembled from coil-rod-coil molecules can be interconnected by addition of a small amount of rod-coil-rod molecule as a bridging agent. Subsequently, these dynamic interconnections lead to stiff bundles composed of cylindrical micelles that are responsible for the formation of a reversible nematic gel. The results described here represent a significant example that dynamic bridging of supramolecular cylinders in aqueous solution can provide a useful strategy to construct one-dimensional nematic structure with three dimensional elastic properties.

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Monte Carlo Simulation of the Molecular Properties of Poly(vinyl chloride) and Poly(vinyl alcohol) Melts

  • Moon, Sung-Doo;Kang, Young-Soo;Lee, Dong-J.
    • Macromolecular Research
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    • v.15 no.6
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    • pp.491-497
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    • 2007
  • NPT Monte Carlo simulations were performed to calculate the molecular properties of syndiotactic poly(vinyl chloride) (PVC) and syndiotactic poly(vinyl alcohol) (PVA) melts using the configurational bias Monte Carlo move, concerted rotation, reptation, and volume fluctuation. The density, mean square backbone end-to-end distance, mean square radius of gyration, fractional free-volume distribution, distribution of torsional angles, small molecule solubility constant, and radial distribution function of PVC at 0.1 MPa and above the glass transition temperature were calculated/measured, and those of PVA were calculated. The calculated results were compared with the corresponding experimental data and discussed. The calculated densities of PVC and PVA were smaller than the experimental values, probably due to the very low molecular weight of the model polymer used in the simulation. The fractional free-volume distribution and radial distribution function for PVC and PVA were nearly independent of temperature.

Development of a FRET-based High-Throughput Screening System for the Discovery of Hsp90 Inhibitors

  • Oh, Sang-Mi;Ko, Yeon-Jin;Lee, Han-Jae;Kim, Jong-Hoon;Chung, Young-Sun;Park, Seung-Bum
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3229-3232
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    • 2011
  • A FRET-based high-throughput screening system was developed for the discovery of competitive smallmolecule Hsp90 inhibitors. The biarsenical fluorescein derivative FlAsH and dabcyl-conjugated Hsp90 inhibitor GM were employed as the FRET donor and quencher, respectively. The spatial proximity perturbation between FlAsH-labeled Hsp90N and GM-dabcyl upon treatment of a small molecule led to changes in the FRET-induced fluorescence, monitored in a high-throughput fashion.

Growth Retardation of Escherichia coli and Staphylococcus aureus by Leek Extract (부추 추출무에 의한 Escherichia coli 및 Staphylococcus aureus의 생육 저해효과)

  • 이민경;이정아;박인식
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.1
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    • pp.196-198
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    • 2001
  • The growth retardation of Escherichia coli and Staphylococcus aureus by heat or acid treated leek (Allium tuberosum) extract was observed. Antimicrobial activity of the leek was the most effective when fresh leek extract was used, but it was stable after heat treatment at 68$^{\circ}C$ for 30 min or 98$^{\circ}C$ for 20 min. It was also relatively stable after incubated at pH 2.0 for 3 hrs. The antimicrobial activity in leek was not detected after dialysis with molecular weight cutoff of 12,000. Therefore it seems to be small molecule with molecular weight lower than 12,000.

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Morphology control of inkjet-printed small-molecule organic thin-film transistors with bank structures

  • Kim, Yong-Hoon;Park, Sung-Kyu
    • Journal of Information Display
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    • v.12 no.4
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    • pp.199-203
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    • 2011
  • Reported herein is the film morphology control of inkjet-printed 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) organic thin-film transistors for the improvement of their performance and of the device-to-device uniformity. The morphology of the inkjetted TIPS-pentacene films was significantly influenced by the bank geometry such as the bank shapes and confinement area for the channel region. A specific confinement size led to the formation of uniform TIPS-pentacene channel layers and better electrical properties, which suggests that the ink volume and the solid concentration of the organic-semiconductor solutions should be considered in designing the bank geometry.