• 제목/요약/키워드: natural sciences and engineering

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Photoreceptor Topography of the Hamster Retina

  • Yu, Song-Hee;Kim, Hyun-Jin;Lee, Eun-Shil;Jeon, Chang-Jin
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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    • pp.52.1-52.1
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    • 2008
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Ginseng-derived type I rhamnogalacturonan polysaccharide binds to galectin-8 and antagonizes its function

  • Yi Zheng;Yunlong Si;Xuejiao Xu;Hongming Gu;Zhen He;Zihan Zhao;Zhangkai Feng;Jiyong Su;Kevin H. Mayo;Yifa Zhou;Guihua Tai
    • Journal of Ginseng Research
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    • 제48권2호
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    • pp.202-210
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    • 2024
  • Background: Panax ginseng Meyer polysaccharides exhibit various biological functions, like antagonizing galectin-3-mediated cell adhesion and migration. Galectin-8 (Gal-8), with its linker-joined N- and C-terminal carbohydrate recognition domains (CRDs), is also crucial to these biological processes, and thus plays a role in various pathological disorders. Yet the effect of ginseng-derived polysaccharides in modulating Gal-8 function has remained unclear. Methods: P. ginseng-derived pectin was chromatographically isolated and enzymatically digested to obtain a series of polysaccharides. Biolayer Interferometry (BLI) quantified their binding affinity to Gal-8, and their inhibitory effects on Gal-8 was assessed by hemagglutination, cell migration and T-cell apoptosis. Results: Our ginseng-derived pectin polysaccharides consist mostly of rhamnogalacturonan-I (RG-I) and homogalacturonan (HG). BLI shows that Gal-8 binding rests primarily in RG-I and its β-1,4-galactan side chains, with sub-micromolar KD values. Both N- and C-terminal Gal-8 CRDs bind RG-I, with binding correlated with Gal-8-mediated function. Conclusion: P. ginseng RG-I pectin β-1,4-galactan side chains are crucial to binding Gal-8 and antagonizing its function. This study enhances our understanding of galectin-sugar interactions, information that may be used in the development of pharmaceutical agents targeting Gal-8.

New Photoreactive Materials Having Chalcone Units: Synthesis and Photoalignment of Nematic Liquid Crystals

  • Lee, Won-Joo;Lim, Ji-Chul;Paek, Sang-Hyon;Kigook Song;Chang, Ji-Young
    • Macromolecular Research
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    • 제9권6호
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    • pp.339-344
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    • 2001
  • In order to investigate the photoalignment mechanism of nematic liquid crystals on a polymer film, a new photoreactive polymer having chalcone groups as side chains was synthesized. Linearly polarized UV light causes preferential photoreactions of the chalcone unit along the polarization direction and thus induces the anisotrpy in the polymer alignment layer resulting in homogeneous LC alignment perpendicular to the polarization direction. The sequential investigations of photoalignment generated by the preferential E/Z isomerization and (2+2) cycloaddition reactions show that either photoreaction can solely induce the LC alignment in the direction perpendicular to UV polarization.

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