Operating mechanism and chemomechanics of the F1-ATPase molecular motor
Ming S. Liu1 B. D. Todd and Richard J. Sadus
1ming@it.swin.edu.au, Centre for Molecular Simulation, Swinburne University of Technology
Enzyme F1-ATPase catalyzes the hydrolysis of ATP and converts chemical energy into
mechanical rotation with exceptionally high efficiency. It performs cellular functions like a
rotary energy-transducing molecular motor and thus promises unique applications in
nanobiotechnology. To better understand the operating mechanism and chemomechanics of
F1-ATPase, we propose a simulation model based on the binding-change schemes, enzyme
kinetics and Langevin dynamics. We show that the torsional energy and stepwise rotation can
be regulated by a series of near-equilibrium reactions when ATP molecules are hydrolyzed.
An effective æratchetÆ drag is also derived to account the motorÆs unidirectional spin.
Complex schemes of binding-changes may exist in the F1-ATPase motor at different
operating conditions. The chemomechanics described in this work is of fundamental
importance to all ATP-fueled motor proteins.