| Project/Area Number |
15570164
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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 |
Cell biology
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| Research Institution | University of Hyogo (2004)
Himeji Institute of Technology (2003) |
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Principal Investigator |
TUZI Satoru University of Hyogo, Graduate School of Life Science, Department of Life Science, Associate Professor, 大学院・生命理学研究科, 助教授 (60227387)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Satoru University of Hyogo, Graduate School of Life Science, Department of Life Science, Research Associate, 大学院・生命理学研究科, 助手 (20347529)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | solid state NMR / phospholipase C / PH domain / signal transduction pathway / lipid bilayer / biomembrane / peripheral membrane protein / higher order structure |
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| Research Abstract |
In 2003, we have established a technique of introduction of ^<13>C isotope labels into PLC-δ1 PH domain, and performed structural study of the PH domain at the membrane surface by using the solid state ^<13>C NMR spectroscopy. In 2004, (1)changes of the membrane binding structure of the PH domain induced at the negatively charged membrane surface were investigated, and (2)methods of ^<13>C isotope labeling of the remaining domains (EF-hand, XY, and C2) of PLC-δ1 were established.
The structure of the PH domain was found to be strongly influenced by acidic lipid contents of the membranes. In the presence of 20% of acidic lipid, phosphatidylserine, PH domain takes a structure similar to that in the solution instead of the previously reported membrane-binding structure observed at the electrically neutral membrane surface. The structural changes observed by the solid-state ^<13>C NMR spectroscopy revealed that the electrostatic repulsions between the negatively charged membrane surface and the charged residues of the PH domain prevent non-specific hydrophobic interaction between the amphipathic α2-helix of the PH domain and the hydrophobic inner layer of the membrane which causes the unique membrane-binding structure of the PH domain at the neutral membrane surface. Increase in the mobility of the PH domain was also observed at the negatively charged membrane surface. Those dependences of the dynamic structure of the PH domain on the lipid composition of membrane might related to responses of the PLC-δ1 to physiological changes of local lipid compositions such as a formation of lipid micro domain and a change of asymmetry of lipid bilayer.
Methods of ^<13>C labeling and preparation of solid state NMR samples of the PH-EF fragment, EF-hand domain and intact PLC-δ1 have been established in this year. These samples will be utilized to investigate inter-domain interactions between PLC-δ1 domains at the membrane surface.
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