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.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: The power stroke of a motor protein: The motor protein EF-G generates a power stroke of 89 pN during ribosome translocation. This mechanical force is obtained by measuring the force-induced dissociation of a series of DNA-mRNA duplexes. The dissociation is indicated by a decrease in magnetic signal.
    Angewandte Chemie International Edition 12/2013; 52(52):14041-4. · 11.34 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: • Cardiac V3 myosin generates slower actin filament velocities and higher average isometric forces (in an in vitro motility assay) when compared with the V1 isoform. • To account for differences in V1 and V3 force and motion generation at the molecular level, we characterized the mechanics and kinetics of single V1 and V3 myosin molecules using a dual laser trap setup. • No differences in either unitary displacement (≈7 nm) or force (≈0.8 pN) were observed between isoforms; however, the duration of unitary displacement events was significantly longer for the V3 isoform at MgATP concentrations > 10 m. • Our results were interpreted on the basis of a cross-bridge model in which displacement event durations were determined by the rates of MgADP release from, and MgATP binding to, myosin. • We propose that the release rate of MgADP from V3 myosin is half that of V1 myosin without any difference in their rates of MgATP binding; thus, kinetic differences between the two cardiac myosin isoforms are sufficient to account for their functional diversity.
    The Journal of Physiology 09/2004; 519(3):669 - 678. · 4.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Optics is usually integrated into robotics as part of intelligent vision systems. At the microscale, however, optical forces can cause significant acceleration and so optical trapping and optical manipulation can enable the noncontact actuation of microcomponents. Microbeads are ubiquitous optically actuated structures, from Ashkin's pioneering experiments with polystyrene beads to contemporary functionalized beads for biophotonics. However, micro- and nanofabrication technologies are yielding a host of novel synthetic structures that promise alternative functionalities and new exciting applications. Recent works on the actuation of synthetic microstructures using optical trapping and optical manipulation are examined in this review. Extending the optical actuation down to the nanoscale is also presented, which can involve either direct manipulation of nanostructures or structure-mediated approaches where the nanostructures form part of larger structures that are suitable for interfacing with diffraction-limited optical fields.
    Laser & Photonics Review 07/2013; 7(4). · 7.98 Impact Factor


Available from