著者

坂本 泰一

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.60, no.2-3, pp.129-134, 2018-05-31 (Released:2018-06-02)

参考文献数

25

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Aptamers are nucleic acids that bind to a target molecule with high affinity and specificity, which are selected from systematic evolution of ligands by exponential enrichment (SELEX). Because of their high affinity and specificity, aptamers are strong candidates of next generation molecular targeted agents. However, for the development of aptamer therapeutics, chemical modification of aptamers is required to improve their nuclease resistance. For the efficient modification, structural information could be important. In this review, I describe structural biology of aptamers.

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.25, no.1, pp.21-37, 1983

著者

佐々木 聡

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.4, pp.267-279, 1996-08-30 (Released:2010-09-30)

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This article provides an opportunity for young researchers and students to familiarize themselves with the use of the International Tables for Crystallography.

著者

石田 英子 大戸 梅治 清水 敏之

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.59, no.2-3, pp.108-113, 2017-06-30 (Released:2017-07-01)

参考文献数

19

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Fertilization, the crucial step in sexual reproduction, requires the fusion of haploid sperm and egg to create a genetically distinct offspring. Despite many studies on mammalian fertilization, the molecular mechanisms underlining the membrane fusion remain largely unknown. At present, IZUMO1 on the sperm surface and JUNO on the egg surface are known as the only protein pair essential for fertilization. In this review, we focus on the crystal structures of human IZUMO1, JUNO and IZUMO1-JUNO complex. These structures reveal the molecular mechanism of mammalian gamete recognition, and provide information for development of non-hormonal contraceptive agents.

著者

角戸 正夫

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.15, no.6, pp.402-415, 1973-12-20 (Released:2010-09-30)

参考文献数

8

著者

長野 晃三

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.11, no.1, pp.25-42, 1969-03-31 (Released:2010-09-30)

参考文献数

48

著者

大崎 健次

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.13, no.2, pp.57, 1971-04-25 (Released:2010-09-30)

著者

仙石 徹

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.3, pp.227-228, 2021-08-31 (Released:2021-09-02)

参考文献数

5

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Cyclic β-amino acids, such as (1R,2R)-2-aminocyclohexane carboxylic acid (ACHC), are known to induce compact conformation of peptides by forming turns and helices. Recently, a method to incorporate cyclic β-amino acids into peptides using ribosomes has been reported. Combining this method with the mRNA display method enabled the de novo discovery of macrocyclic peptides that contain cyclic β-amino acid residues and efficiently inhibit human coagulation factor XIIa (FXIIa). One such peptide, F3, potently inhibits FXIIa (Ki: 1.5 nM) and contains two ACHC residues. In the co-crystal structure of FXIIa-F3, F3 adopts an antiparallel β-hairpin structure stabilized by two ACHC residues. Despite its smaller size, F3 engages its target in a manner similar to that of natural protein-based inhibitors of serine proteases, demonstrating the utility of foldamer library consisting of macrocyclic peptides containing cyclic β-amino acids.

著者

芝内 孝禎 笠原 成 松田 祐司 福田 竜生 杉本 邦久

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.55, no.2, pp.128-134, 2013-04-30 (Released:2013-05-01)

参考文献数

59

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Strongly interacting electrons can exhibit novel collective phases, among which the electronic nematic phases are perhaps the most surprising as they spontaneously break rotational symmetry of the underlying crystal lattice. Our highly sensitive magnetic torque measurements under in-plane field rotation in iron-based superconductors BaFe2(As1-xPx)2 provide evidence for the electronic nematic ordering below a characteristic temperature T*. High-resolution crystal-structure analysis by using synchrotron X-ray reveals small but finite orhthorhobic distortionbelow T* and the orthorhombicity shows a big jump at a lower temperature Ts. The results imply an electronic origin of rotational symmetry breaking, whose relation to superconductivityis discussed.

著者

和田 啓

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.2, pp.105-112, 2021-05-31 (Released:2021-06-05)

参考文献数

31

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Oxygen is needed to produce energy for aerobic organism. Oxygen molecule exhibits high reactivity, thereby constantly leading to super-reactive molecules called reaction oxygen species. My research has focused on the system involved in the cellular redox control including the O2-sensing, H2O2-scavenging and protecting the cells, and have revealed their molecular mechanisms by means of the structural, biochemical and spectroscopic analyses.

著者

平野 良憲

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.2, pp.77-78, 2021-05-31 (Released:2021-06-05)

参考文献数

9

著者

加藤 昌子

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.63, no.1, pp.2-7, 2021-02-28 (Released:2021-03-04)

参考文献数

19

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Soft crystals, which are defined as flexible response systems with high structural order, respond to gentle stimuli such as vapor exposure and rubbing but maintain their ordered structures and exhibit remarkable visual changes in their shape, color, and luminescence. This article focuses on the soft crystals composed of platinum(Ⅱ) complexes bearing aromatic ligands that exhibit characteristic luminescence by assembly. When the complex units are stacked with short Pt…Pt contacts, a new emission state called 3MMLCT (i.e. metal-metal-to-ligand charge transfer) are generated on the basis of the Pt…Pt electronic interaction, and the 3MMLCT energy can change by the slight deformation of the stacking structure in response to gentle stimuli. These properties make platinum(Ⅱ) complexes soft crystals, and the precise control of the Pt…Pt interaction and other intermolecular interactions enables the precise control of photofunctions beyond the existing limitation.

著者

安永 卓生

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.61, no.1, pp.43-50, 2019-02-28 (Released:2019-03-02)

参考文献数

57

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The electron cryo-microscopy is one of the most powerful techniques to elucidate biological molecular structure under nearly physiological condition. By single particle analysis, many three-dimensional structures of proteins and their complexes have been resolved at atomic resolutions. Furthermore, in situ molecular behaviours in cells and tissues have also been reported at nano-meter or sub-nanometer resolutions by electron tomography. I would here review current situations of electron cryo-microscopy and the principles of their analysis and so show its possibility.

著者

海野 昌喜 松井 敏高 齋藤 正男

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.53, no.3, pp.213-218, 2011-06-30 (Released:2011-07-13)

参考文献数

19

被引用文献数

2

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X-ray crystallographic analysis of a metalloprotein requires knowing the electronic state of the metal center, if one wants to elucidate the exact function and/or reaction mechanism. As an example, we show our recent structural analysis of the heme oxygenase reaction intermediate which is involved in the third step of the heme degradation reaction. The reaction intermediate was crystallized under anaerobic condition, and the obtained crystals were frozen into liquid nitrogen. The absorption spectra of the single crystal before and after X-ray irradiation were compared with that of the frozen solution in 100 K cold nitrogen stream. The determined structure offers the first solid evidence for the presence of a water cluster in the distal pocket of this catalytically critical intermediate. This structure combined with the QM/MM calculation supports our proposal that the biliverdin is produced via Fe-OOH verdoheme intermediate.

著者

桐山 良一

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.13, no.1, pp.2-9, 1971-02-25 (Released:2010-09-30)

参考文献数

29

著者

小澤 芳樹

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.59, no.5, pp.201-202, 2017-10-31 (Released:2017-11-03)

参考文献数

12

著者

橋爪 大輔

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.56, no.5, pp.313-318, 2014-10-31 (Released:2014-10-31)

参考文献数

7

被引用文献数

4

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Multipole expansion method is frequently used for refinements on electron density distribution of organic compound and metal complex crystals aiming at understanding nature of chemical bonds and intra- and inter-molecular interactions. In this article, short introduction of the method, and procedures on experiments and refinements are presented. Electron density distribution analysis of a singlet biradical compound generated in C-P-C-P four-membered ring is also presented. Topological analysis based on Atoms in Molecules theory is performed.

著者

奥地 拓生 プレジャブ ナランゴー 富岡 尚敬

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.59, no.6, pp.309-315, 2017-12-31 (Released:2017-12-31)

参考文献数

30

被引用文献数

1

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Water in the Earth has been transported from the oceans into its deep interior, where it forms hydrous deep mantle minerals. Wadsleyite [(Mg,Fe)2SiO4] has been considered as one of the most important host minerals incorporating this type of water as hydroxyl groups. To constrain the capacity of water in its structure and also to understand the effect of such water on its physical properties, it is essential to quantitatively determine the hydrogenʼs site and occupancy in the wadsleyite structure. Here we conduct a neutron time-of-flight single-crystal Laue diffraction study of it. Single crystals, which have size and quality suitable for this method, were successfully synthesized by a slow-cooling method at the relevant high pressure and temperature condition. The results unambiguously demonstrate a unique incorporation mechanism of hydrogen into the wadsleyite structure.

著者

都築 誠二

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.61, no.4, pp.224-230, 2019-12-15 (Released:2019-12-15)

参考文献数

18

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Dispersion corrected density functional theory (DFT) calculation is a powerful method for the refinement of crystal structures. This article presents a short introduction of computational methods and some examples of the refinements including the effects of the refinement on the calculated intermolecular interaction energies between neighboring molecules in crystals.

著者

遠藤 太佳嗣 西川 惠子

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.58, no.1, pp.7-12, 2016-02-29 (Released:2016-03-02)

参考文献数

29

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Here we review our recent works on thermal phase behaviors of ionic liquids, 1-alkyl-3-methylimidazolium hexafluorophosphates ([Cnmim]PF6, n=1~4). Their complex thermal phase behaviors observed in calorimetric measurements were investigated at the molecular level using combined techniques of Raman spectroscopy, quantum chemical calculations, X-ray analyses, and nuclear magnetic resonance spectroscopy. It was demonstrated that the conformational flexibility of the side chain in the cation played a key role for thermal phase behaviors of some ILs as represented by [C4mim]PF6, nevertheless, which was not always the case for others as evidenced in [C1mim]PF6 results.