Nonlinear Actin Deformations Lead to Network Stiffening, Yielding, and Nonuniform Stress Propagation.

ABSTRACT: We use optical tweezers microrheology and fluorescence microscopy to apply nonlinear microscale strains to entangled and cross-linked actin networks, and measure the resulting stress and actin filament deformations. We couple nonlinear stress response and relaxation to the velocities and displacements of individual fluorescent-labeled actin segments, at varying times throughout the strain and varying distances from the strain path, to determine the underlying molecular dynamics that give rise to the debated nonlinear response and stress propagation of cross-linked and entangled actin networks at the microscale. We show that initial stress stiffening arises from acceleration of strained filaments due to molecular extension along the strain, while softening and yielding is coupled to filamen

SUBMITTER: Gurmessa B 

PROVIDER: S-EPMC5627063 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature