Journal ArticleDOI
Single myosin molecule mechanics: piconewton forces and nanometre steps
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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.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.read more
Citations
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Journal ArticleDOI
Contractility parameters of human β-cardiac myosin with the hypertrophic cardiomyopathy mutation R403Q show loss of motor function
Suman Nag,Ruth F. Sommese,Zoltan Ujfalusi,Ariana C. Combs,Stephen J. Langer,Shirley Sutton,Leslie A. Leinwand,Michael A. Geeves,Kathleen M. Ruppel,James A. Spudich +9 more
TL;DR: A detailed characterization of the most debated HCM-causing mutation in human β-cardiac myosin, R403Q is presented, predicting a lower unloaded duty ratio of the motor.
Journal ArticleDOI
Cell-sized liposomes reveal how actomyosin cortical tension drives shape change
Kevin Carvalho,Kevin Carvalho,Feng-Ching Tsai,Edouard Lees,Edouard Lees,Raphaël Voituriez,Raphaël Voituriez,Gijsje H. Koenderink,Cécile Sykes,Cécile Sykes +9 more
TL;DR: The results suggest that cells must precisely control their contractility to remain intact during cellular events, and propose a physical model based on a balance of active tension and mechanical resistance to rupture.
Journal ArticleDOI
Mechanical coupling between myosin molecules causes differences between ensemble and single-molecule measurements.
TL;DR: Using a combination of simulations and theory, it is shown that the kinetic mechanism derived from single-molecule experiments describes ensemble behavior; but the connection between single molecule and ensemble is complex.
Journal ArticleDOI
Coupling between phosphate release and force generation in muscle actomyosin.
TL;DR: Newer crystal forms and other structural data suggest that closing of the actin-binding cleft opens switch I (presumably decreasing nucleotide affinity), which is consistent with the order of events suggested before: myosin.
Journal ArticleDOI
Biochemical kinetic characterization of the Acanthamoeba myosin-I ATPase.
E M Ostap,Thomas D. Pollard +1 more
TL;DR: This work determined the rate constants for key steps on the myosin-I ATPase pathway using fluorescence stopped-flow, cold-chase, and rapid-quench techniques to obtain insights about the evolution of all myOSin isoforms.
References
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Journal ArticleDOI
Proposed Mechanism of Force Generation in Striated Muscle
A. F. Huxley,R. M. Simmons +1 more
TL;DR: Recordings of the change in tension in striated muscle after a sudden alteration of the length have made it possible to suggest how the force between the thick and thin muscle filaments may be generated.
Journal ArticleDOI
Three-dimensional structure of myosin subfragment-1: a molecular motor
Ivan Rayment,Wojciech Rypniewski,Karen Schmidt-Bäse,Karen Schmidt-Bäse,Robert Smith,Diana R. Tomchick,Diana R. Tomchick,Matthew M. Benning,Donald A. Winkelmann,Gary E. Wesenberg,Hazel M. Holden +10 more
TL;DR: The three-dimensional structure of the head portion of myosin, or subfragment-1, which contains both the actin and nucleotide binding sites, is described, and this structure of a molecular motor was determined by single crystal x-ray diffraction.
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Direct observation of kinesin stepping by optical trapping interferometry
TL;DR: It is found that kinesin moves with 8-nm steps, similar to biological motors that move with regular steps.
Journal ArticleDOI
The Mechanism of Muscular Contraction
TL;DR: There is now a real possibility of solving the problem in complete detail, provided a way can be found to crystallize a recently purified globular subfragment of the myosin molecule, and some apparently paradoxical properties of the system are revealed.
Journal ArticleDOI
Bead movement by single kinesin molecules studied with optical tweezers
TL;DR: The results of this study are consistent with a model in which kinesin detaches briefly from the microtubule during a part of each mechanochemical cycle, rather than a models in whichKinesin remains bound at all times.