Single myosin molecule mechanics: piconewton forces and nanometre steps

Nature. 1994 Mar 10;368(6467):113-9. doi: 10.1038/368113a0.


A new in vitro assay using a feedback enhanced laser trap system allows direct measurement of force and displacement that results from the interaction of a single myosin molecule with a single suspended actin filament. Discrete stepwise movements averaging 11 nm were seen under conditions of low load, and single force transients averaging 3-4 pN were measured under isometric conditions. The magnitudes of the single forces and displacements are consistent with predictions of the conventional swinging-crossbridge model of muscle contraction.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / physiology
  • Adenosine Triphosphate / physiology
  • Animals
  • Biomechanical Phenomena
  • Feedback
  • In Vitro Techniques
  • Myosin Subfragments
  • Myosins / physiology*
  • Rabbits


  • Actins
  • Myosin Subfragments
  • Adenosine Triphosphate
  • Myosins