• Title/Summary/Keyword: biological molecules

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Computational Study on the Dependence of Electronic Transition Energies of Porphin, Chlorin, Mg-Chlorin and Chlorophyll a on an External Charge

  • Kwon, Jang Sook;Yang, Mino
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.453-459
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    • 2013
  • In phtosynthetic light harvesting complexes, the electronic transition energies of chlorophylls are influenced by the Coulombic interaction with nearby molecules. Variation of the interactions caused by structural inhomogeneity in biological environment results in a distribution of disordered electronic transition energies of chlorophylls. In order to provide a practical guide to predict qualitative tendency of such distribution, we model four porphyrin derivatives including chlorophyll a molecule interacting with an external positive charge and calculate their transition energies using the time dependent density functional method. It is found that ${\pi}-{\pi}^*$ transition energies of the molecules are generally blue-shifted by the charge because this stabilizes occupied molecular orbitals to a greater extent than unoccupied ones. Furthermore, new transitions in the visible region emerge as a result of the red-shift in energy of an unoccupied Mg orbital and it is suggested that light-induced electron transfer may occur from the tetrapyrrole ring to the central magnesium when the molecules are interacting with a positive charge.

In-cell nuclear magnetic resonance spectroscopy for studying intermolecular interactions

  • Sugiki, Toshihiko;Lin, Yuxi;Lee, Young-Ho
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.1
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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.

Analysis of the Dimerization of Human CD99 Using Bimolecular Fluorescence Complementation Technique

  • Lee, Mi-Kyung;Kim, Hyun-Soo;Kim, Seung-Seok;Cho, Myung-Hwan;Lee, Im-Soon
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.472-476
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    • 2008
  • Two isoforms of human CD99 have been identified, but only heterotypic interaction between the isomers was recently demonstrated. In this study, we performed bimolecular fluorescence complementation analysis to further characterize the interaction in vivo. Upon transiently transfecting plasmids expressing either of the two isoforms fused with yellow fluorescent protein (YFP) fragments, all the YFP-tagged CD99 molecules were properly localized on cell surfaces, and formed fluorescent dimers. Interestingly, however, unlike the previous report, the homodimers formed as efficiently as the heterodimer via their extracellular domains, implying its distinct regulatory role through modulating the complex profile.

Generation and Fates of Supernumerary Centrioles in Dividing Cells

  • Shin, Byungho;Kim, Myung Se;Lee, Yejoo;Jung, Gee In;Rhee, Kunsoo
    • Molecules and Cells
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    • v.44 no.10
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    • pp.699-705
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    • 2021
  • The centrosome is a subcellular organelle from which a cilium assembles. Since centrosomes function as spindle poles during mitosis, they have to be present as a pair in a cell. How the correct number of centrosomes is maintained in a cell has been a major issue in the fields of cell cycle and cancer biology. Centrioles, the core of centrosomes, assemble and segregate in close connection to the cell cycle. Abnormalities in centriole numbers are attributed to decoupling from cell cycle regulation. Interestingly, supernumerary centrioles are commonly observed in cancer cells. In this review, we discuss how supernumerary centrioles are generated in diverse cellular conditions. We also discuss how the cells cope with supernumerary centrioles during the cell cycle.

DRG2 Deficiency Causes Impaired Microtubule Dynamics in HeLa Cells

  • Dang, Thao;Jang, Soo Hwa;Back, Sung Hoon;Park, Jeong Woo;Han, In-Seob
    • Molecules and Cells
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    • v.41 no.12
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    • pp.1045-1051
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    • 2018
  • The developmentally regulated GTP binding protein 2 (DRG2) is involved in the control of cell growth and differentiation. Here, we demonstrate that DRG2 regulates microtubule dynamics in HeLa cells. Analysis of live imaging of the plus-ends of microtubules with EB1-EGFP showed that DRG2 deficiency (shDRG2) significantly reduced the growth rate of HeLa cells. Depletion of DRG2 increased 'slow and long-lived' subpopulations, but decreased 'fast and short-lived' subpopulations of microtubules. Microtubule polymerization inhibitor exhibited a reduced response in shDRG2 cells. Using immunoprecipitation, we show that DRG2 interacts with tau, which regulates microtubule polymerization. Collectively, these data demonstrate that DRG2 may aid in affecting microtubule dynamics in HeLa cells.

Biotechnology and Biomedicine - a Case Study with Recombinant Limulus Factor C

  • Ling, Ding-Jeak;Ho-Bow
    • Biomedical Science Letters
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    • v.8 no.1
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    • pp.1-5
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    • 2002
  • Biotechnology "embraces everything from the production of recombinant proteins to the use of biological molecules as components of nanotechnology". Strategic-basic research in biotechnology is crucial to boosting world economy and creating jobs in the Life Sciences. Biotechnology will be the benefit to be drawn from biomedical life science research, which promises to be the new pillar of economy. Although the turnaround time for life science research products is painstakingly slow, the fruits of one such labour (Fig. 1), is being reaped fur worldwide biomedical applications.

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Human Genome Project (인간유전체 사업)

  • Kwon, Oh-Joo
    • Korean Journal of Biological Psychiatry
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    • v.8 no.2
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    • pp.196-202
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    • 2001
  • The completion of the rough draft of the human genome is a remarkable achievement. It provides the overall structures of huge DNA molecules that constitute the genome and an outline of the information needed to create a human being. This paper reviewed new ideas, projects, and scientific advances made by the Human Genome Project. We also discussed the future of medicine and biomedical research in postgenomic era.

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Revisiting Hepatoprotective Natural Products from a Biological Point of View

  • Kim, Hong-Pyo;Kim, Young-Choong
    • Natural Product Sciences
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    • v.17 no.3
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    • pp.165-174
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    • 2011
  • Naturally occurring small molecules from plants, microorganisms, and animals allow the design of drugs that can be beneficial in virtually all kinds of human diseases. Liver diseases with diverse etiologies such as viral infection, chemical intoxication, and metabolic fat accumulation are one of the leading causes of human mortality. Unfortunately, however, there are few effective drugs available capable of stopping or reversing the progress of liver disease. Here, we discuss the current advances in developing hepatoprotective natural products for several arrays of liver disease pathogenesis.

Fast Growing Furious Races for Targeting Fibroblast Growth Factor Receptors

  • Park, Daechan
    • Molecules and Cells
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    • v.45 no.11
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    • pp.789-791
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    • 2022
  • Targeting fibroblast growth factor receptors (FGFRs) has been slow compared to other targeted cancer therapies for receptor tyrosine kinases, such as epidermal growth factor receptors. The low efficacy and variable response have limited the growth of FGFR inhibitors in clinical use. Nevertheless, recent systematic and genomic approaches have identified the biological conditions for effectively targeting FGFRs and can accelerate the development of targeted drugs. Under clinical and preclinical trials, the inhibitors started fast growing furious races to target FGFRs. Finally, FGFRs will be more actionable and targetable with more precise and effective drugs at the end of the race, passing the finish line.

Synthesis and Biological Effects of 2, 3-Diphenyl-5-Methoxyindole and Substituted Benzophenone Derivatives

  • Hishmat, O.H.;El-Sbabrawy, O.A.;Nakkady, S.S.;Mahmoud, S.S.
    • Archives of Pharmacal Research
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    • v.12 no.3
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    • pp.149-153
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    • 1989
  • Seven 2, 3-diphenyl-5-methoxyindole derivatives were synthesized. The effect of structural variation of these molecules on biological activities was examined. None of the tested compounds was found to be toxic up 5 gm/Kg body weight. Four compounds demonstrated smooth muscle relaxant effects and one showed a persistent hypotensive effect. Only the parent compound, 2, 3-diphenyl-5-methoxyindole, showed a significant analgesic effect.

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