| Project/Area Number |
08640751
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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 |
機能・物性・材料
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| Research Institution | Suntory Institute for Bioorganic Research |
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Principal Investigator |
IWASHITA Takashi Suntory Institute for Bioorganic Research, Chief Chemist, 主任研究員 (00150144)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIYA Noriko Suntory Institute for Bioorganic Research, Researcher, 研究員 (20236102)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | bacteriorhodopsin / fluorotryptophan / proton-pump / MALDI-TOF MS / X-ray diffraction / CD / 固体NMR / レチナ-ルアナログ |
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| Research Abstract |
Membrane proteins like receptors which contain alpha-helices play an important role in the biological system. Bacteriorhodopsin is a kind of photoreceptors which has 7 alpha-helices and it is thought to be the model of GTP-binding protein coupled receptors. Tryptophan residues of bacteriorhodopsin were labeled by ^<19>F on their imidazole ring to obtain strucural informations using the ^<19>Fsolid-state NMR.However, the signals from ^<19>F might be overlapped, so that 4-F, 5-F and 6-F-tryptophan were tested to overcome the problem. We obtained three kind of fluorinated bacteriorhodopsin. The fluorinated bacteriorhodopsin which contains 6-F-tryptophan has different property from others on the purification step by sucrose gradient and the MALDI-TOF MS.Usually, bacteriorhodopsins form two dimensional trimer crystal on the membrane. Howerver, it is clarified that the bacteriorhodopsin which contains 6F-tryptophan makes no crystal structure from X-ray diffraction analysis and CD spectrum.
To study the distnance between two fluorines in the opsin and the chromophor, the synthetic chromophor which had an aromatic ring with a CF_3 group was incorporated to the fluorine labeled bacterioopsin with 5-F-tryptophan. The magnetization transfer due to the dipolar-dipolar coupling was inestigated. It seems that the magnetization transfer might be observed by 1 dimensional RFDR and 2 dimensional CP/EXCY experiments. Next, MELODRAMA pulse sequence was tested for the observation of magnetization transfer. The MELODRAMA spectrum showed the anti-phase cross-peaks to the diagonal peaks. This means that the observation of magnetization transfer between the fluorinated opsin and the CF3 group of the synthetic chromophore has been confirmed.
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