Single myosin molecule mechanics: piconewton forces and nanometre steps.
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.
Finer
J T
JT
Department of Biochemistry, Beckman Center, Stanford University School of Medicine, California 94305.
Simmons
R M
RM
Spudich
J A
JA
D000199:Actins / Q000502:physiology; D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001696:Biomechanical Phenomena; D005246:Feedback; D066298:In Vitro Techniques; D015879:Myosin Subfragments; D009218:Myosins / Q000502:physiology*; D011817:Rabbits
D000199:Actins; D015879:Myosin Subfragments; D000255:Adenosine Triphosphate; D009218:Myosins