Chemomechanical regulation of myosin Ic cross-bridges: Deducing the elastic properties of an ensemble from single-molecule mechanisms
Fig 3
Modeled probability distributions of the states of myosin Ic’s cross-bridge cycle.
(a) For physiological nucleotide concentrations and 100 μM actin, myosin Ic is largely unbound from actin under small forces. Considering only the strongly bound states, the ADP state (3) dominates for small forces and the ATP state (5) for forces larger than 1.5 pN. (b) A highly increased actin concentration of 10 mM populates the weakly bound ADP⋅Pi state (2) for small forces and myosin is mostly bound to the filament. (c) The occupancy of the ADP state (3) is increased by a raised ADP concentration of 250 mM and dominates for forces smaller than 2 pN and larger than 4 pN.