Microtubules soften due to cross-sectional flattening

• DOI: 10.7554/elife.34695
• Publication Date: 2018-06-01T12:00:14Z
• Authors: Edvin Memet; Feodor Hilitski; Margaret A Morris; Walter J Schwenger; Zvonimir Dogic; L Mahadevan
• Keywords: Flattening

We use optical trapping to continuously bend an isolated microtubule while simultaneously measuring the applied force and resulting filament strain, thus allowing us determine its elastic properties over a wide range of strains. find that, in low-strain regime, microtubules may be quantitatively described terms classical Euler-Bernoulli filament, above critical strain they deviate from this simple model, showing softening response with increasingdeformations. A three-dimensional thin-shell which increased mechanical compliance is caused by flattening eventual buckling cross-section, captures effect high regime yields quantitative values effective microtubules. Our results demonstrate that are highly dependent on magnitude offer new interpretation for large variety data measured different methods.