| Project/Area Number |
07558215
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Structural biochemistry
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MORISHIMA Isao Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (50026093)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Satoshi Kyoto University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (30283641)
ISHIMORI Koichiro Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (20192487)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | High Pressure Muiti-Nuclear NMR / High Presure Flash Photolysis / Hemoproteins / Electron Transfer in Proteins |
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| Research Abstract |
The primary results in this research project are as follows :
(1)Development of High Pressure Multi-Dimensional NMR Spectroscopy. We have tried to measure 2-dimensional proton NMR spectrum of hemoprotein under high pressure (up to 2000 bar). Our preliminary measurement in normal pressure has revealed that the very high sample concentration (more than 10 mM) and 40-60 hours accumulation would be required to obtain the 2D NMR spectrum by using a glass capillary as sample tube. Although the glass capillary needs enough space below the detection coil in the NMR probe, the bottom part of the our probe was used for the temperature control unit, which severely limits the size of the glass capillary. We final concluded that our NMR probe must be modified to use the glass capillary.
(2)Application of High Pressure Laser Flash Photolysis to Dynamic Properties of Hemoproteins. Since pressure has been considered to perturb thermal fluctuation in protein structure, we examined the effects of the thermal fluctuation on dynamic properties of hemoprotein. One of the dynamic properties we focused on in this research project was the ligand binding in hemoproteins. Systematic combination of mutant myoglobins and kinetic measurement under high pressure has clearly shown that the some of the hydrophobic amino acid residues play a key role in controlling the ligand binding by maintaining the high hydrophobic environments in the heme pocket. Another dynamic property is the electron transfer reaction in hemoproteins. Basied on the measurements of the reaction rates for electron transfer in hemoprotein (myoglobin) under high pressure, we can pointed out that the electron transfer pathway and free energy difference for the reaction would highly depend on the thermal fluctuation in protein structure, and the thermal fluctuation is one of the critical factors of the molecular mechanism for the electron transfer in proteins.
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