1999 Fiscal Year Final Research Report Summary
Development of scanning optical force microscopy and its application to imaging of the plasma membrane in live cells
| Project/Area Number |
09358014
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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 |
Biophysics
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| Research Institution | Nagoya University |
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Principal Investigator |
KUSUMI Akihiro Nagoya University Graduate School of Science Professor, 大学院・理学研究科, 教授 (50169992)
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| Project Period (FY) |
1997 – 1999
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| Keywords | optical trap / cantilever / scanning force microscope / cell membrane / colloidal gold / latex bead / membrane protein / membrane skeleton |
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| Research Abstract |
Recent experimental work on single protein diffusion has shown that most proteins diffuse in the plasma membrane through a hopping between small sub-micron domains. The membrane skeleton has been shown to play an important role in regulating this anomalous diffusion. To image the barriers to free diffusion in the plasma membrane, a gold probe, sparsely coated with antibody, bound to the membrane protein CD44, (one that had been previously undergoing diffusion) was trapped in an optical tweezers and dragged in a raster scan across an area on a live NRK cell surface. Deviation in the probe's position from the center of the trap signifies a force applied on the gold-CD44 complex by the constituents of the membrane. This measured force is used to image the barriers to free movement. Networks of barriers with a mesh size of about 0.5-1 um were imaged that are presumably due to the membrane skeleton. The force required to pass the barriers was <0.5 pN and is dependent on the rate of scanning and the spring constant of the trap, as expected. Scans were performed within the following parameters : 2x2 micron area, scanning rate 0.5-2 um/s, trap stiffness 1-5 pN/mm.
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