日本結晶学会誌
Online ISSN : 1884-5576
Print ISSN : 0369-4585
ISSN-L : 0369-4585
55 巻 , 4 号
選択された号の論文の11件中1~11を表示しています
連載企画 産業界で活躍する結晶学
最近の研究から
  • 矢島 健, 坂口 辰徳, 小林 洋治, 陰山 洋, 辻本 吉廣
    2013 年 55 巻 4 号 p. 242-247
    発行日: 2013/08/31
    公開日: 2013/08/31
    ジャーナル フリー
    We prepared oxyhydrides of the perovskite ATiO3A=Ba, Sr, Ca) via low-temperature reduction using CaH2. The obtained oxyhydrides are stable against temperature as well as A-site substitution, and the hydride species are exchangeable with outer hydrogen gas, implying the hydride diffusion through the lattice. The exchange temperature depends on the A-site cation,and ranged from 380-460 ℃. Epitaxial thin films of these oxyhydrides were also fabricated. The films show a metallic conductivity.
  • 田中 良樹
    2013 年 55 巻 4 号 p. 248-253
    発行日: 2013/08/31
    公開日: 2013/08/31
    ジャーナル フリー
    MATE (multidrug and toxic compound extrusion) family transporters are conserved in the three primary kingdoms, and export xenobiotics using an electrochemical gradient of H+ or Na+ across the membrane.1) MATE transporters confer multidrug resistance (MDR) to bacterial pathogens2) and cancer cells.3) Therefore, the development of MATE inhibitors has long been awaited in the field of clinical medicine.4) Here we present the crystal structures of the H+-driven MATE transporter from Pyrococcus furiosus in two distinct apo-form conformations, and in complexes with a derivative of the antibacterial drug norfloxacin and three in vitro selected thioether-macrocyclic peptides. The structures, combined with functional analyses, revealed that the protonation of Asp41 on the N-terminal lobe induces the bending of TM1, which in turn collapses the N-lobe cavity, thereby extruding the substrate drug to the extra-cellular space. Moreover, two of the macrocyclic peptides bind the central cleft in distinct manners, which correlate with their inhibitory activities.
  • 志波 智生, 高橋 元, 原田 繁春, 斎本 博之, 城戸 康年, 稲岡 ダニエル健, 北 潔
    2013 年 55 巻 4 号 p. 254-259
    発行日: 2013/08/31
    公開日: 2013/08/31
    ジャーナル フリー
    The cyanide-insensitive alternative oxidase (AOX) is a diiron carboxylate protein that catalyzes the four-electron reduction of dioxygen to water by ubiquinol. In Trypanosoma brucei, a parasite that causes human African sleeping sickness, AOX plays a critical role in the survival of the parasite in its bloodstream form. Since AOX is absent from mammals, this protein represents a novel and promising therapeutic target. We determined the first crystal structures of the trypanosomal alternative oxidase in the absence and presence of ascofuranone and its derivatives, which are drug candidates for African trypanosomiasis. All structures reveal that AOX is a homodimer with a non-haem diiron carboxylate active-site buried within a four-helix bundle.
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