Powerstroke defined

We have tried to show how the current structural, biochemical, and mechanical evidence can be used to provide an oudine of how actin binding, Pj release, and the powerstroke may be coupled. However, concrete evidence remains in short supply. The structural states will be hard to define if they are coupled to equilibrium constants with values close to unity and fast rate constants (100—1000 s-1). Only in the presence of a large load, which brings the system close to an isometric condition, will the structural states have significant occupancy during a steady state. The use of stalled processive motors such as myosins V or VI may be one way of trapping the relevant structures. 

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