An estimate to the first approximation of microtubule rupture force.

An estimate to the first approximation of microtubule rupture force.
Eur Biophys J. 2019 May 27;:
Authors: Endow SA, Marszalek PE
Abstract
Microtubule mechanical properties are essential for understanding basic cellular processes, including cell motility and division, but the forces that result in microtubule rupture or breakage have not yet been measured directly. These forces are essential to understand the mechanical properties of the cytoskeleton and responses by cells to both normal conditions and stress caused by injury or disease. Here we estimate the force required to rupture a microtubule by analyzing kinesin-14 Ncd motor-induced microtubule breakage in ensemble motility assays. We model the breakage events as caused by Ncd motors pulling or pushing on single microtubules that are clamped at one end by other motors attached to the glass surface. The number of pulling or pushing Ncd motors is approximated from the length of the microtubule bound to the surface and the forces produced by the pulling or pushing motors are estimated from forces produced by the Ncd motor in laser-trap assays, reported by others. Our analysis provides an estimate, to the first approximation, of ~ 500 pN for the minimal force required to rupture a 13-pf microtubule. The value we report is close to the forces estimated from microtubule stretching/fragmentation experiments and overlaps with the forces applied by AFM in microtubule indentation ass...

Source: European Biophysics Journal : EBJ - May 26, 2019 Category: Physics Authors: Endow SA, Marszalek PE Tags: Eur Biophys J Source Type: research