Elastic response, buckling, and instability of microtubules under radial indentation.

Published

Journal Article

We tested the mechanical properties of single microtubules by lateral indentation with the tip of an atomic force microscope. Indentations up to approximately 3.6 nm, i.e., 15% of the microtubule diameter, resulted in an approximately linear elastic response, and indentations were reversible without hysteresis. At an indentation force of around 0.3 nN we observed an instability corresponding to an approximately 1-nm indentation step in the taxol-stabilized microtubules, which could be due to partial or complete rupture of a relatively small number of lateral or axial tubulin-tubulin bonds. These indentations were reversible with hysteresis when the tip was retracted and no trace of damage was observed in subsequent high-resolution images. Higher forces caused substantial damage to the microtubules, which either led to depolymerization or, occasionally, to slowly reannealing holes in the microtubule wall. We modeled the experimental results using finite-element methods and find that the simple assumption of a homogeneous isotropic material, albeit structured with the characteristic protofilament corrugations, is sufficient to explain the linear elastic response of microtubules.

Full Text

Duke Authors

Cited Authors

  • Schaap, IAT; Carrasco, C; de Pablo, PJ; MacKintosh, FC; Schmidt, CF

Published Date

  • August 2006

Published In

Volume / Issue

  • 91 / 4

Start / End Page

  • 1521 - 1531

PubMed ID

  • 16731557

Pubmed Central ID

  • 16731557

Electronic International Standard Serial Number (EISSN)

  • 1542-0086

International Standard Serial Number (ISSN)

  • 0006-3495

Digital Object Identifier (DOI)

  • 10.1529/biophysj.105.077826

Language

  • eng