Dynamic properties of molecular motors in the divided-pathway model.

The mechanisms of molecular motors transport are important for understanding multiple biological processes. Recent single-molecule experiments indicate that motor proteins myosin V moves along protein filaments via a complex biochemical pathway that consists of sequentially coupled linear and parallel two-chain segments. We investigate analytically the corresponding discrete-state stochastic divided-pathway model for molecular motors transport. Explicit expressions are obtained for velocities and dispersions. The dynamic properties of motor proteins in the divided-pathway model are compared with those in single-chain linear and parallel-pathway stochastic models. It is argued that modifying biochemical pathways has a strong effect on the dynamic properties, and it allows motor proteins to be more flexible in performing their biological functions.