A Mechanistic Model of the Motility of Actin Filaments on Myosin
D.V. Nicolau_Jr. and D.V. Nicolau
Swinburne University, AU
Keywords: molecular motors, motility, actin, myosin
The motility of acto-myosin is crucial to cell motility, muscular contraction, cell division etc.; and recently to several hybrid dynamic devices based on protein molecular motors. In a sense, the in vitro motility assay, which involves the motion of e.g. actin filaments on a substrate coated with myosin used extensively to investigate the dynamics of the acto-myosin system, is a primitive hybrid nanodevice. Following our previous work, and using actin-myosin motility experiments on flat homogeneous; flat patterned and micro-profiled surfaces we propose a new mechanical model of actin motility on myosin, wherein a filament is modeled as a chain of beads connected by harmonic springs, with a limitation on the stretching of the filament. The rotation of one bead with respect to its neighbors is constrained in similar way. We implemented this model and used Monte Carlo simulations to determine whether it can predict the directionality of filament motion. The principal advantage of this model over our previous one is that we replaced the empirically correct assumption that the filament moves like a worm i.e. the head determines the direction of movement and the rest of the filament follows the head. The simulation can be used for the future design of nanodevices based on protein linear molecular motors.
Nanotech 2004 Conference Technical Program Abstract