To resolve the individual mechanical events of force generation by actomyosin, we have developed a new technique to capture and directly manipulate individual myosin subfragment-1 (S1) molecules using a scanning probe. The unitary mechanical step during sliding along an actin filament is 5.3nm, but 2 to 5 rapid steps in succession often end up with total displacements of ∼11 to ∼30nm. Multiple steps are produced by single heads during the hydrolysis of a single ATP molecule.
