Jump to main content
Jump to site search

Issue 40, 2017
Previous Article Next Article

Scale dependence of the mechanics of active gels with increasing motor concentration

Author affiliations

Abstract

Actin is a protein that plays an essential role in maintaining the mechanical integrity of cells. In response to strong external stresses, it can assemble into large bundles, but it grows into a fine branched network to induce cell motion. In some cases, the self-organization of actin fibers and networks involves the action of bipolar filaments of the molecular motor myosin. Such self-organization processes mediated by large myosin bipolar filaments have been studied extensively in vitro. Here we create active gels, composed of single actin filaments and small myosin bipolar filaments. The active steady state in these gels persists long enough to enable the characterization of their mechanical properties using one and two point microrheology. We study the effect of myosin concentration on the mechanical properties of this model system for active matter, for two different motor assembly sizes. In contrast to previous studies of networks with large motor assemblies, we find that the fluctuations of tracer particles embedded in the network decrease in amplitude as motor concentration increases. Nonetheless, we show that myosin motors stiffen the actin networks, in accordance with bulk rheology measurements of networks containing larger motor assemblies. This implies that such stiffening is of universal nature and may be relevant to a wider range of cytoskeleton-based structures.

Graphical abstract: Scale dependence of the mechanics of active gels with increasing motor concentration

Back to tab navigation

Supplementary files

Publication details

The article was received on 13 Jul 2017, accepted on 17 Sep 2017 and first published on 18 Sep 2017


Article type: Paper
DOI: 10.1039/C7SM01391D
Citation: Soft Matter, 2017,13, 7352-7359
  •   Request permissions

    Scale dependence of the mechanics of active gels with increasing motor concentration

    A. Sonn-Segev, A. Bernheim-Groswasser and Y. Roichman, Soft Matter, 2017, 13, 7352
    DOI: 10.1039/C7SM01391D

Search articles by author

Spotlight

Advertisements