Non-Gaussian athermal fluctuations in active gels

• DOI: 10.1039/c0sm00925c
• Publication Date: 2011-02-21T13:30:27Z
• Authors: Toshihiro Toyota; David A. Head; Christoph F. Schmidt; Daisuke Mizuno
• Keywords: Microrheology; Thermal fluctuations; Mean squared displacement; Molecular motor; Tracking (education)

Dynamic networks designed to model the cell cytoskeleton can be reconstituted from filamentous actin, motor protein myosin and a permanent cross-linker. They are driven out of equilibrium when molecular motors active. This gives rise athermal fluctuations that recorded by tracking probe particles dispersed in network. We have here probed such "active gels" using video microrheology. measured full distribution displacements, also known as van Hove correlation function. The dominant influence thermal or detected varying lag time over which displacements measured. argue exponential tails derive single close probes, we extract an estimate velocity heads along actin filaments. exhibits central Gaussian region assume derives action many independent proteins far dominate. Recording whole rather than just typically second moment (mean-squared displacement) thus allowed us differentiate between effect individual collective motors.