Mechanical fatigue in microtubules

Mechanical failure of biological nanostructures due to sustained force application has been studied in great detail. In contrast, fatigue failure arising from repeated application of subcritical stresses has received little attention despite its prominent role in engineering and potentially biology. Here, taxol-stabilized microtubules are up to 256 times bent into sinusoidal shapes of varying wavelength and the frequency of breaking events are observed. These experiments allow the calculation of fatigue life parameters for microtubules. Repeated buckling due to 12.5% compression – equal to the compression level experienced by microtubules in contracting cardiomyocytes – results in failure after in average 5 million cycles, whereas at 20% compression failure occurs after in average one thousand cycles. The fatigue strength (Basquin) exponent B is estimated as -0.06. , , , # Mechanical fatigue in microtubules

[https://doi.org/10.5061/dryad.6hdr7sr3v](https://doi.org/10.5061/dryad.6hdr7sr3v)

## Description of the data and file structure

**Supplementary Videos 1\-5 \| 12\.5% Compression Assays\.**
Videos of the compression assays of fluorescently labeled microtubules undergoing 12.5% compression on flexible PDMS surface coated with kinesin-1. Each video contains 13 frames, two for each measured compression cycle (1, 4, 16, 32, 64, and 256), alternating between the compressed and subsequent relaxed stage of the cycle. The final frame of each video is a stretch of 2.5% after 256 compression cycles that is used to identify breaking events. Field of View: 277.33 μm x 234.00 μm.
**Supplementary Videos 6\-15 \| 20% Compression Assays\.**
Videos of the compression assays of fluorescently labeled microtubules undergoing 20% compression on flexible PDMS surface coated with kinesin-1. Each video contains 9 frames, two for each measured compression cycle (1, 2, 4, ...