Single Molecule Measurements of Molecular Motors

2008 ◽  
Author(s):  
Yoshiharu Ishii ◽  
Toshio Yanagida
Keyword(s):  
Single Molecule ◽  
Molecular Motors

scholarly journals A model of processive walking and slipping of kinesin-8 molecular motors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ping Xie
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
External Load ◽  
Molecular Motor ◽  
Velocity Versus ◽  
Stick Slip ◽  
Load Dependence ◽  
Chemomechanical Coupling ◽  
Similarities And Differences ◽  
Stick Slip Motion

AbstractKinesin-8 molecular motor can move with superprocessivity on microtubules towards the plus end by hydrolyzing ATP molecules, depolymerizing microtubules. The available single molecule data for yeast kinesin-8 (Kip3) motor showed that its superprocessive movement is frequently interrupted by brief stick–slip motion. Here, a model is presented for the chemomechanical coupling of the kinesin-8 motor. On the basis of the model, the dynamics of Kip3 motor is studied analytically. The analytical results reproduce quantitatively the available single molecule data on velocity without including the slip and that with including the slip versus external load at saturating ATP as well as slipping velocity versus external load at saturating ADP and no ATP. Predicted results on load dependence of stepping ratio at saturating ATP and load dependence of velocity at non-saturating ATP are provided. Similarities and differences between dynamics of kinesin-8 and that of kinesin-1 are discussed.

scholarly journals Single-molecule FRET dynamics of molecular motors in an ABEL trap

Methods ◽  
2021 ◽  
Author(s):  
Maria Dienerowitz ◽  
Jamieson A.L. Howard ◽  
Steven D. Quinn ◽  
Frank Dienerowitz ◽  
Mark C. Leake
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Single Molecule Fret

Molecular Motors: Force and Movement Generated by Single Myosin II Molecules

Physiology ◽  
2002 ◽  
Vol 17 (5) ◽  
pp. 213-218 ◽  
Author(s):  
Caspar Rüegg ◽  
Claudia Veigel ◽  
Justin E. Molloy ◽  
Stephan Schmitz ◽  
John C. Sparrow ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Single Molecule ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Myosin Ii ◽  
Force Production ◽  
Myosin Isoforms ◽  
Single Molecule Level ◽  
Recent Developments ◽  
Muscle Myosin

Muscle myosin II is an ATP-driven, actin-based molecular motor. Recent developments in optical tweezers technology have made it possible to study movement and force production on the single-molecule level and to find out how different myosin isoforms may have adapted to their specific physiological roles.

scholarly journals Stochastically pumped adaptation and directional motion of molecular machines

2018 ◽  
Vol 115 (38) ◽  
pp. 9405-9413 ◽  
Author(s):  
R. Dean Astumian
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
High Efficiency ◽  
Probability Distributions ◽  
Molecular Machines ◽  
High Energy ◽  
Stochastic Thermodynamics ◽  
Recent Developments ◽  
Directional Motion ◽  
External Fluctuations

Recent developments in synthetic molecular motors and pumps have sprung from a remarkable confluence of experiment and theory. Synthetic accomplishments have facilitated the ability to design and create molecules, many of them featuring mechanically bonded components, to carry out specific functions in their environment—walking along a polymeric track, unidirectional circling of one ring about another, synthesizing stereoisomers according to an external protocol, or pumping rings onto a long rod-like molecule to form and maintain high-energy, complex, nonequilibrium structures from simpler antecedents. Progress in the theory of nanoscale stochastic thermodynamics, specifically the generalization and extension of the principle of microscopic reversibility to the single-molecule regime, has enhanced the understanding of the design requirements for achieving strong unidirectional motion and high efficiency of these synthetic molecular machines for harnessing energy from external fluctuations to carry out mechanical and/or chemical functions in their environment. A key insight is that the interaction between the fluctuations and the transition state energies plays a central role in determining the steady-state concentrations. Kinetic asymmetry, a requirement for stochastic adaptation, occurs when there is an imbalance in the effect of the fluctuations on the forward and reverse rate constants. Because of strong viscosity, the motions of the machine can be viewed as mechanical equilibrium processes where mechanical resonances are simply impossible but where the probability distributions for the state occupancies and trajectories are very different from those that would be expected at thermodynamic equilibrium.

[12] Molecular motors and single-molecule enzymology

2003 ◽  
pp. 228-245 ◽  
Author(s):  
Yoshiharu Ishii ◽  
Kazuo Kitamura ◽  
Hiroto Tanaka ◽  
Toshio Yanagida
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Single Molecule Enzymology

scholarly journals A Generalized Kinetic Model for Coupling between Stepping and ATP Hydrolysis of Kinesin Molecular Motors

2019 ◽  
Vol 20 (19) ◽  
pp. 4911 ◽  
Author(s):  
Xie ◽  
Guo ◽  
Chen
Keyword(s):  
Kinetic Model ◽  
Atpase Activity ◽  
Single Molecule ◽  
Rate Constants ◽  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Power Production ◽  
Wild Type ◽  
Chemomechanical Coupling ◽  
Generalized Kinetic Model

A general kinetic model is presented for the chemomechanical coupling of dimeric kinesin molecular motors with and without extension of their neck linkers (NLs). A peculiar feature of the model is that the rate constants of ATPase activity of a kinesin head are independent of the strain on its NL, implying that the heads of the wild-type kinesin dimer and the mutant with extension of its NLs have the same force-independent rate constants of the ATPase activity. Based on the model, an analytical theory is presented on the force dependence of the dynamics of kinesin dimers with and without extension of their NLs at saturating ATP. With only a few adjustable parameters, diverse available single molecule data on the dynamics of various kinesin dimers, such as wild-type kinesin-1, kinesin-1 with mutated residues in the NLs, kinesin-1 with extension of the NLs and wild-type kinesin-2, under varying force and ATP concentration, can be reproduced very well. Additionally, we compare the power production among different kinesin dimers, showing that the mutation in the NLs reduces the power production and the extension of the NLs further reduces the power production.

scholarly journals The physics of life: one molecule at a time

2013 ◽  
Vol 368 (1611) ◽  
pp. 20120248 ◽  
Author(s):  
Mark C. Leake
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Living Organism ◽  
Biological Processes ◽  
Robust Methods ◽  
Erwin Schrödinger ◽  
Biophysical Analysis ◽  
Spatial Boundary ◽  
New Generation ◽  
Near Future

The esteemed physicist Erwin Schrödinger, whose name is associated with the most notorious equation of quantum mechanics, also wrote a brief essay entitled ‘What is Life?’, asking: ‘How can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?’ The 60+ years following this seminal work have seen enormous developments in our understanding of biology on the molecular scale, with physics playing a key role in solving many central problems through the development and application of new physical science techniques, biophysical analysis and rigorous intellectual insight. The early days of single-molecule biophysics research was centred around molecular motors and biopolymers, largely divorced from a real physiological context. The new generation of single-molecule bioscience investigations has much greater scope, involving robust methods for understanding molecular-level details of the most fundamental biological processes in far more realistic, and technically challenging, physiological contexts, emerging into a new field of ‘single-molecule cellular biophysics’. Here, I outline how this new field has evolved, discuss the key active areas of current research and speculate on where this may all lead in the near future.

scholarly journals Insights into the mechanisms of myosin and kinesin molecular motors from the single-molecule unbinding force measurements

2010 ◽  
Vol 7 (suppl_3) ◽  
Author(s):  
Sergey V. Mikhailenko ◽  
Yusuke Oguchi ◽  
Shin'ichi Ishiwata
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Force Measurements ◽  
Cellular Functions ◽  
Mechanochemical Cycle ◽  
The Individual ◽  
Experimental Geometry ◽  
External Loads ◽  
Individual Motor

In cells, ATP (adenosine triphosphate)-driven motor proteins, both cytoskeletal and nucleic acid-based, operate on their corresponding ‘tracks’, that is, actin, microtubules or nucleic acids, by converting the chemical energy of ATP hydrolysis into mechanical work. During each mechanochemical cycle, a motor proceeds via several nucleotide states, characterized by different affinities for the ‘track’ filament and different nucleotide (ATP or ADP) binding kinetics, which is crucial for a motor to efficiently perform its cellular functions. The measurements of the rupture force between the motor and the track by applying external loads to the individual motor–substrate bonds in various nucleotide states have proved to be an important tool to obtain valuable insights into the mechanism of the motors' performance. We review the application of this technique to various linear molecular motors, both processive and non-processive, giving special attention to the importance of the experimental geometry.

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