Non-Gaussian curvature distribution of actin-propelled biomimetic colloid trajectories

Stephan Schmidt (1, 2, 3, 4, 5) , Jasper van der Gucht (6) , P. Maarten Biesheuvel , Richard Weinkamer (1, 2, 3, 4, 5) , Emmanuèle Helfer (7) , Andreas Fery (1, 2, 3, 4, 5)

1 Neurologische Gemeinschaftspraxis [Bonn, Germany]
2 Department of Biomaterials [Potsdam]
3 MPI CIR - Max Planck Institute of Colloid and Interface Research
4 Universität Bayreuth
5 Max-Plank-Institut für Kolloid und Grenzflächenforschung
6 Laboratory of Physical Chemistry and Soft Matter
7 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

We analyze the motion of colloids propelled by a comet-like tail of polymerizing actin filaments. The curvature of the particle trajectories deviates strongly from a Gaussian distribution, implying that the underlying microscopic processes are fluctuating in a non-independent manner. Trajectories for beads of different size all showed the same non-Gaussian behavior, while the mean curvature decreased weakly with size. A stochastic simulation that includes nucleation, force-dependent dissociation, growth, and capping of filaments, shows that the non-Gaussian curvature distribution can be explained by a positive feedback mechanism in which attached chains under higher tension are more likely to snap.

Mots clés: Actin Propulsion Trajectory analysis Stochastic simulation; Actin; Propulsion; Trajectory analysis; Stochastic simulation

Domaines: Physique [physics]; Matière Molle [cond-mat.soft]; Biophysique [physics.bio-ph]

Stephan Schmidt, Jasper van der Gucht, P. Maarten Biesheuvel, Richard Weinkamer, Emmanuèle Helfer, et al.. Non-Gaussian curvature distribution of actin-propelled biomimetic colloid trajectories. European Biophysics Journal, 2008, 37, pp.1361-1366. ⟨10.1007/s00249-008-0340-x⟩. ⟨hal-04393817⟩