Mechanical stability of microtubules investigated under unidirectional strain using combined fluorescence microscopy and high-speed atomic force microscopy

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K03889
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
• Research Institution: Center for Novel Science Initatives, National Institutes of Natural Sciences
• 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)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: Microtubules / HS-AFM / TIRFM / deformation

Outline of Final Research Achievements

An elastic substrate stretching device to be used with a tip-scan high-speed atomic force microscope (HS-AFM) was develeloped and used to load microtubules fixed by sparsely distributed kinesin. Due to the elastic substrate experiencing simultaneous tension and compression caused by Poisson's effect, buckling of microtubules could be recorded in a controlled manner. Imaging was perfomed with a resolution of several nanometers, surpassing the resolution of conventional fluorescence microscopy. Further, stretching of microtubules could also be observed, which lead to the microtubules fracturing and depolymerizing.
Using a different approach, microtubules were self-assembled into rings by DNA-modification on kinesin substrates. These rings turned out to have a complex 3D structure that was elucidated by combined HS-AFM and TIRFM.

Free Research Field

Materials Science

Academic Significance and Societal Importance of the Research Achievements

A system that allows to intrinsically apply stress to any number of samples was developed and can be used study membrane mechanics or mechanical properties of soft material on a large scale. Furthermore, ring-shaped microtubule swarms could be utilized as motors for nanomachines.