Single myosin molecule mechanics: piconewton forces and nanometre steps.

Department of Biochemistry, Beckman Center, Stanford University School of Medicine, California 94305.
Nature (Impact Factor: 38.6). 04/1994; 368(6467):113-9. DOI: 10.1038/368113a0
Source: PubMed

ABSTRACT 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.

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