| Project/Area Number |
09640612
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Himeji Institute of Technology |
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Principal Investigator |
NAITO Akira Department of Life Science, Himeji Institute of Technology Associate Professor, 理学部, 助教授 (80172245)
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| Co-Investigator(Kenkyū-buntansha) |
TUZI Satoru Department of Life Science, Himeji Institute of Technology Assistant Professor, 理学部, 助手 (60227387)
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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 |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | Ion channel / Enkephalin / Melittin / Interatomic distance / High resolution solid state NMR / Three-dimensional structure / Phospholipid bilayer / Magnetically oriented membrane / アラメシチン / バイセル / イオンチャンネル / 膜分断 / 膜融合 |
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| Research Abstract |
In this research project, we have studied to achieve a new approach to determine the three-dimensional structure and orientation of membrane bound ion channel peptides. Following results were obtained in this research project.
(1) The three-dimensional structure of [ィイD113ィエD1C, ィイD115ィエD1N]-labeled Leu-enkephalin (tyr-Gly-Gly-Phe-Leu) dihydrate crystals was determined on the basis of six sets of accurately determined ィイD113ィエD1C-ィイD115ィエD1N interatomic distances by rotational echo double resonance (REDOR) and some additional constraints from ィイD113ィエD1C chemical shifts.
(2) Interatomic distances of isotopically doubly labeled N-Acetyl-Pro-Gly-Phe crystals, obtained from rotational echo double resonance (REDOR) experiments, were analyzed as a three-spin system in which observed nuclei are simultaneously coupled with isotopically labeled intra- and intermolecular heteronuclei. In particular, the intermolecular dipolar interaction was examined to obtain a clue as to the relative orientation of a given molecule to the surrounding neighbors. We have developed a systematic procedure to determine both the intra- and intermolecular interatomic distances and the angle between three two interatomic vectors.
(3) The conformation and dynamics of melittin bound to the dimyristoylphophatidylcholin (DMPC) bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state ィイD131ィエD1P and ィイD113ィエD1C NMR spectroscopy. Using ィイD131ィエD1P NMR, it was found that melittin-DMPC bilayer system forms magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature. ィイD113ィエD1C NMR spectra were observed on the ィイD113ィエD1C labeled melittin bound to the lipid bilayers. Finally, it was found that melittin adopts a transmembrane a-helix whose average axis is parallel to the bilayer normal.
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