| Project/Area Number |
17340126
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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 |
Biophysics/Chemical physics
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| Research Institution | Meiji University |
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Principal Investigator |
YOSHIMURA Hideyuki Meiji University, Department of Physics, Professor (70281441)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANO Takashi Tokyo Institute of Technology, Department of Mechanical and Aerospace Engineering, Assistant (00183517)
MOMOZONO Satoshi Tokyo Institute of Technology, Department of Mechanical and Aerospace Engineering, Assistant (70262300)
AIZAWA Shin-ichi Prefectural University of Hiroshima, Department of Life Science, Professor (50222451)
TACHIKAWA Mki Meiji University, Department of Physics, Professor (60201612)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,490,000 (Direct Cost: ¥15,800,000、Indirect Cost: ¥690,000)
Fiscal Year 2007: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2006: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2005: ¥11,400,000 (Direct Cost: ¥11,400,000)
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| Keywords | flagella / polyhook / Young's modulus / rigidity / fluorescence / electronmicroscopy / rapid freezing / freeze dry / レーザトラップ |
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| Research Abstract |
Flagellated bacteria like Sal. Typhimurium swims by rotating helical flagella filaments with bundling and synchronizing them each other. Because axs of bacterial motors directed in different way, flexible joint part is required between motor and flagella filament. It is known that bacterial hook work as a universal joint of this part. However its mechanical feature like rigidity is not known exactly. Here we measured modulus of rigidity by using polyhook filament, length about 1μm, from mutant Sal. Typhimurium(SWJ108). Purified polyhook filaments were frozen rapidly in liquid ethane and freeze dried. Distribution of helix pitch and diameter were evaluated from electron micrographs of shadowed images. We got value of 95±23nm for helix pitch and 31±9.9nm for diameter of polyhook filament. We also measured fluctuation of helical pitch and diameter of flagella filament from negative stained samples. By comparing fluctuation of polyhook and flagella filaments, we have calculated the ratio of rigidity as G_<flagella>/G<hook>=120. According to the literature value of flagella filament rigidity, 3.8×10^9Pa, we obtained rigidity of polyhook as 3.3×10^7Pa. We also tried to measure the rigidity of flagella in solution directly using thin glass capillary. Fluorescent labeled flagella filament was fixed by anti-flagellin adsorbed on a glass capillary of diameter less than 1μm. Tension in pN range was measured from bending deformation of glass capillary under fluorescent microscope. We are now accumulating the results in this process. We are going to measure rigidity of super-poly hook which has length of few micro-meter by the same method.
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