| Project/Area Number |
09044218
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Field |
Functional biochemistry
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
AIBARA Shigeo Res. Inst. for Food Sci., Foof Structure and Functionality, Kyoto University, Assc. Prof., 食糧科学研究所, 助教授 (20027197)
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| Co-Investigator(Kenkyū-buntansha) |
YAMANE Takashi Graduate School of Engineering, Dept. of Biotechnology, Nagoya University, Professor, 大学院・工学研究科, 教授 (80030055)
デルーカス ローレンスJ. アラバマ大学, バーミンガム校・巨大分子結晶解析センター, 教授
DELUCAS Lowrence Center for Macromolecular Crystallograph, Univ. of Alabama at Birmingham, U. S. A., Professor
デルーカス ローレンス アラバマ大学, バーミンガム校・高分子結晶解析センター, 教授
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥8,700,000 (Direct Cost: ¥8,700,000)
Fiscal Year 1998: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1997: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | Lysozyme / Protein crystal growth / Vapor difusion method / X-ray crystallography / Molecular packing / Water structure / Microgravity / Space shuttle / X線結晶構造解析 / 結晶成長 / ニワトリ卵白リゾチーム / 宇宙 / ハンギングドロップ法 / 単斜晶 / 正方晶 |
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| Research Abstract |
Crystallization experiment of hen egg-white lysozyme according to the vapor diffusion method was carried out by using the space shuttle under the microgravity environment in space, and the influences of microgravity on the protein crysta growth was considered from the aspect of the structure biology. The crystallization apparatuses produced according to the principle of the vapor diffusion method were used.
Four kinds of single crystals containing 3 different crystal systems (monoclinic, orthorhombic (20℃ and 37℃) and tetragonal (pH0.7 and pH0.1) crystals) were crystallized on the ground and in space environments, and the crystallographic data of them were compared with each other. Of the two different shapes of monoclinic crystals, one is a rectangular form and the other is an extremely thin palate-like form. They are easily distinguished from each other by their appearances. In the space experiments, there was a strong likelihood of the latter crystals appearing. However, the molecula
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r packing in the crystal from the results of X-ray crystallographic analysis although the crystal lattice of these crystals were slightly different. The difference in the morphology is, therefore, considered to be derived from difference in the growth rate of the crystal plane. Regarding orthorhombic crystals, the molecular packing of the space-grown crystals were quite different from that of the high temperature forms which are transformed under the temperature conditions higher than 30℃ from the ground -grown tetragonal or monoclinic crystals.
After X-ray crystallographic analyses of seven crystals from the three different space groups (monoclinic, orthorhombic and tetragonal forms of the space- and earth-grown crystals), their molecular structure were compared. Significant differences among the molecular structures were not found between the space- and ground-grown crystals although they had some relatively fluctuating regions in the molecular surface. Regarding the water structure bound to the protein, three highly or dared water molecules were commonly conserved in the hinge region of lysozyme. These facts suggest that the protein structure itself was not influenced by the microgravity but that the interaction of the protein molecules in the nucleation process was significantly affected. In space, it is assumed that the surface characteristics of the protein molecule e. g. the distributions in the formation of crystal nuclei, and the single crystals of better diffraction quality, (less mosaicity) were consequently formed under the micro gravity field in space. Less
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