Multiscale Biomechanics of Actin Filaments and Crosslinked Networks

Tamara C. Bidone, TaeYoon Kim, Marco A. Deriu, Umberto Morbiducci, and Roger D. Kamm


Computational modeling, molecular dynamics, normal mode analysis, actin networks


A multiscale computational approach is applied to actin filaments and actin crosslinked networks. The molecular rearrangements induced by a calcium ion and a magnesium ion bound on then actin monomer (Ca2+-G-actin and Mg2+-G-actin) are incorporated into actin filaments (Ca2+-F-actin and Mg2+-F-actin). The bending and stretching modes of these filaments are evaluated by means of normal mode analysis. Then, the computed bending and stretching stiffness are incorporate into a minimal model system consisting of 12 µM of actin filaments and 0.24 µM of crosslinking proteins. A constant shear strain is applied to the top surface of the network at a rate of 0.1 s-1 and the generated stress in the direction parallel to the applied strain is computed. The lower bending stiffness and higher extensional stiffness of Ca2+- and Mg2+-F-actin, in comparison to the cation free form of F-actin, enhanced the role of the bending mode in the elastic response of the network.

Important Links:

Go Back