日本結晶学会誌
Online ISSN : 1884-5576
Print ISSN : 0369-4585
ISSN-L : 0369-4585
56 巻 , 2 号
選択された号の論文の17件中1~17を表示しています
2.物性研究における結晶学-物性のダイナミズムと結晶構造-
連載企画 産業界で活躍する結晶学
  • 村瀬 浩貴
    2014 年 56 巻 2 号 p. 109-114
    発行日: 2014/04/30
    公開日: 2014/05/01
    ジャーナル フリー
    Our modern confortable lifestyles are supported by advanced fibers and the application fields of the fibers have spread into not only clothing textiles but also industrial uses. The industry of the high strength fibers, which is a typical example of the advanced fiber, has concurrently been grown with the progress of the fiber science including crystallography of polymer crystals. The history of the high strength fibers shedding light on the technologies of molecular manipulation giving rise to the high strength fibers and the related crystallography are summarized in this article. Moreover, a new mechanism of the formation of the flow-induced super structure, “shish-kebab”, with regard to the key-structure of the high strength fibers is shown as a recent topic of flow-induced polymer crystallization.
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  • 横山 武司, 水口 峰之, 日下 勝弘, 田中 伊知朗, 新村 信雄
    2014 年 56 巻 2 号 p. 129-132
    発行日: 2014/04/30
    公開日: 2014/05/01
    ジャーナル フリー
    Transthyretin(TTR)is a plasma protein associated with human amyloid diseases. The dissociation of the TTR tetramer is considered to be the rate-limiting step in amyloid fibril formation. The amyloid fibril formation by TTR is known to be promoted by acidic pH. In order reveal the molecular mechanisms of pH dependence of TTR amyloidogenesis, the neutron crystal structure of TTR was solved at 2.0 Å resolution using IBARAKI Biological Crystal Diffractometer. The neutron structure revealed that His88 was single protonated and involved in a large hydrogen-bond network consisted of Thr75, Trp79, Pro113 and water molecules. The double protonation of His88 by acidification breaks this hydrogen-bond network and causes the destabilization of the TTR tetramer. Furthuermore, the comparison with X-ray structure solved at pH 4.0 indicated that the protonation occurred to Asp74, His88 and Glu89 at pH 4.0. Our structural analysis reveals a wealth of information about the hydrogen bonds and the pH sensitivity in human TTR.
  • 北野 健
    2014 年 56 巻 2 号 p. 133-138
    発行日: 2014/04/30
    公開日: 2014/05/01
    ジャーナル フリー
    The RecQ family of DNA helicases play a key role in protecting the genome against deleterious changes. In humans, mutations in the members WRN (Werner syndrome protein) and BLM (Bloom syndrome protein) respectively lead to rare genetic diseases associated with accelerated aging and cancer predisposition. Recently we determined the 3D structures of human WRN and BLM including a crystal structure of the RecQ C-terminal (RQC) domain bound to a DNA duplex, the first structure of the RecQ-DNA complex. In the complex, the β-wing of the RQC winged-helix motif acts as a scalpel to induce unpairing of a Watson-Crick base pair, an explanation for the unique activities of RecQs toward recombination and repair intermediates such as Holliday junctions.
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