2022 Fiscal Year Annual Research Report
Mechanical stability of microtubules investigated under unidirectional strain using combined fluorescence microscopy and high-speed atomic force microscopy
| Project/Area Number |
20K03889
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| Research Institution | Center for Novel Science Initatives, National Institutes of Natural Sciences |
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Principal Investigator |
Ganser Christian 大学共同利用機関法人自然科学研究機構(新分野創成センター、アストロバイオロジーセンター、生命創成探究, 生命創成探究センター, 特任助教 (50846095)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | microtubules / deformation / HS-AFM |
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| Outline of Annual Research Achievements |
A stretching stage was developed utilizing a polymer-based elastic substrate that can be extended in a controlled manner. Furthermore, the substrate provides simultaneosly tension as well as compression: Along the stretching direction, the substrate experiences tension, however, in the perpendicular direction, the substrate is compressed according to Poisson's effect.
Using sparsely distributed kinesin that was anchored on the surface, microtubules could be fixed securely. Moreover, microtubules were randomly oriented on the surface, some along the stretching axis, some perpendicular to it, with most assuming varying degrees of orientions inbetween.
This allowed the HS-AFM observation of microtubules buckling under stepwise increased compression. A clear relationship between compression and buckling radius was found - the radius decreased with increasing compressive stress. The advantage of this observation is the high resolution on the level of 1 nm, which enabled a clear identification of the point where the the compressive stress caused catastrophic failure.
In a related collaborative investigation, a different approach was used where DNA-modified microtubule swarms on kinesin surface self-assembled into ring structures, which were then observed by HS-AFM to elucidate their detailed structure.
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