Coupling of actin hydrolysis and polymerization: Reduced description   with two nucleotide states
  The polymerization of actin filaments is coupled to the hydrolysis of adenosine triphosphate (ATP), which involves both the cleavage of ATP and the release of inorganic phosphate. We describe hydrolysis by a reduced two-state model with a cooperative cleavage mechanism, where the cleavage rate depends on the state of the neighboring actin protomer in a filament. We obtain theoretical predictions of experimentally accessible steady state quantities such as the size of the ATP-actin cap, the size distribution of ATP-actin islands, and the cleavage flux for cooperative cleavage mechanisms. 
Xin Li, Reinhard Lipowsky and Jan Kierfeld
cond-mat.stat-mech cond-mat.soft physics.bio-ph q-bio.SC