| Project/Area Number |
17380178
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied veterinary science
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| Research Institution | Hokkaido University |
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Principal Investigator |
INANAMI Osamu Hokkaido University, Graduate School of Veterinary Medicine, Associate Professor, 大学院獣医学研究科, 助教授 (10193559)
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| Co-Investigator(Kenkyū-buntansha) |
HORIUCHI Motohiro Hokkaido University, Graduate School of Veterinary Medicine, Professor, 大学院獣医学研究科, 教授 (30219216)
KARIWA Hiroaki Hokkaido University, Graduate School of Veterinary Medicine, Associate Professor, 大学院獣医学研究科, 助教授 (70224714)
INABA Mustumi Hokkaido University, Graduate School of Veterinary Medicine, Professor, 大学院獣医学研究科, 教授 (00183179)
KUWABARA Mikinori Hokkaido University, Graduate School of Veterinary Medicine, Professor, 大学院獣医学研究科, 教授 (10002081)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,900,000 (Direct Cost: ¥15,900,000)
Fiscal Year 2006: ¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 2005: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Keywords | prion / Creutzfeldt-Jacob disease (CJD), / bovine spongiformencephalopathy (BSE) / site-directed spin labeling (SDSL) / nitroxide spin probe / electron spin resonance (ESR) / 3D structure / Structural biology / ニトロオキシドスピンプロ一ブ / BSE / 電子スピン共鳴 / スピンラベル / 双極子相互作用 / 分子間距離 / 銅イオン |
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| Research Abstract |
We examined the influence of D177N (178N in humans) mutation on the conformational stability of the S2 region of moPrPc with varying pHs by using the SDSL-ESR technique. We prepared moPrPc mutants that reacted with methane thiosulfonate spin-probes (Y161R1 and Y161R1/D177N). The ESR spectrum of D177N at pH 7.5 was narrower than that of Y161R1, referred to as WT^*. The ESR spectrum of D177N did not change when pH in the solution decreased from 7.5 to 4.0.These results suggested that the disappearance of a salt bridge (D177-R163) induced the increase in the instability of S2 region. The values of 1/ H of the central component (Mi=0) in the ESR spectrum obtained from WT^* remained constant from pH 7.5 to pH 6.5, whereas an abrupt increase of 1/Ho occurred when the pH in the solution decreased to under 6.0. These findings indicated that the conformational transition from a rigid structure to a flexible structure existed at between pH 6.5 and pH 6.0. Moreover, the line shape of the ESR spectrum obtained from H176S neighboring the salt bridge linked to the S2 region was narrower than that of WT^* at pH 7.5. When the pH in the solution decreased from 7.5 to 4.0, the change in the spectrum of H176S was small. These results indicate that the protonation of H 176 is strongly associated with the stability of S2 region. These findings are important for understanding the mechanism by which the disruption of the salt bridge in the S2 region forms the pathogenic PrP_Sc structure in hereditary Creutzfeldt-Jacob disease and fatal familial insomnia.
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