scholarly journals Temperature-Dependent Activity of Motor Proteins: Energetics and Their Implications for Collective Behavior

2021 ◽  
Vol 9 ◽  
Author(s):  
Saumya Yadav ◽  
Ambarish Kunwar
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Intracellular Transport ◽  
Motor Proteins ◽  
Atp Hydrolysis ◽  
Molecular Motor ◽  
Surrounding Medium ◽  
Biochemical Properties ◽  
Cellular Transport ◽  
Temperature Dependent

Molecular motor proteins are an extremely important component of the cellular transport system that harness chemical energy derived from ATP hydrolysis to carry out directed mechanical motion inside the cells. Transport properties of these motors such as processivity, velocity, and their load dependence have been well established through single-molecule experiments. Temperature dependent biophysical properties of molecular motors are now being probed using single-molecule experiments. Additionally, the temperature dependent biochemical properties of motors (ATPase activity) are probed to understand the underlying mechanisms and their possible implications on the enzymatic activity of motor proteins. These experiments in turn have revealed their activation energies and how they compare with the thermal energy available from the surrounding medium. In this review, we summarize such temperature dependent biophysical and biochemical properties of linear and rotary motor proteins and their implications for collective function during intracellular transport and cellular movement, respectively.

scholarly journals Molecular motors: forty years of interdisciplinary research

2011 ◽  
Vol 22 (21) ◽  
pp. 3936-3939 ◽  
Author(s):  
James A. Spudich
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Molecular Motor ◽  
Single Molecule Level ◽  
In Vitro Motility ◽  
Nonmuscle Cell ◽  
Nonmuscle Cells ◽  
City Plan

A mere forty years ago it was unclear what motor molecules exist in cells that could be responsible for the variety of nonmuscle cell movements, including the “saltatory cytoplasmic particle movements” apparent by light microscopy. One wondered whether nonmuscle cells might have a myosin-like molecule, well known to investigators of muscle. Now we know that there are more than a hundred different molecular motors in eukaryotic cells that drive numerous biological processes and organize the cell's dynamic city plan. Furthermore, in vitro motility assays, taken to the single-molecule level using techniques of physics, have allowed detailed characterization of the processes by which motor molecules transduce the chemical energy of ATP hydrolysis into mechanical movement. Molecular motor research is now at an exciting threshold of being able to enter into the realm of clinical applications.

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.

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 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 Renewal Reward Perspective on Linear Switching Diffusion Systems in Models of Intracellular Transport

2020 ◽  
Vol 82 (10) ◽  
Author(s):  
Maria-Veronica Ciocanel ◽  
John Fricks ◽  
Peter R. Kramer ◽  
Scott A. McKinley
Keyword(s):  
Transport Properties ◽  
Intracellular Transport ◽  
Motor Proteins ◽  
Molecular Motor ◽  
Effective Diffusivity ◽  
Reaction Diffusion ◽  
Model Parameters ◽  
Switching Diffusion ◽  
Diffusion Dynamics ◽  
Effective Transport

Abstract In many biological systems, the movement of individual agents is characterized having multiple qualitatively distinct behaviors that arise from a variety of biophysical states. For example, in cells the movement of vesicles, organelles, and other intracellular cargo is affected by their binding to and unbinding from cytoskeletal filaments such as microtubules through molecular motor proteins. A typical goal of theoretical or numerical analysis of models of such systems is to investigate effective transport properties and their dependence on model parameters. While the effective velocity of particles undergoing switching diffusion dynamics is often easily characterized in terms of the long-time fraction of time that particles spend in each state, the calculation of the effective diffusivity is more complicated because it cannot be expressed simply in terms of a statistical average of the particle transport state at one moment of time. However, it is common that these systems are regenerative, in the sense that they can be decomposed into independent cycles marked by returns to a base state. Using decompositions of this kind, we calculate effective transport properties by computing the moments of the dynamics within each cycle and then applying renewal reward theory. This method provides a useful alternative large-time analysis to direct homogenization for linear advection–reaction–diffusion partial differential equation models. Moreover, it applies to a general class of semi-Markov processes and certain stochastic differential equations that arise in models of intracellular transport. Applications of the proposed renewal reward framework are illustrated for several case studies such as mRNA transport in developing oocytes and processive cargo movement by teams of molecular motor proteins.

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.

scholarly journals Quantifying the Heat Dissipation from Molecular Motor’s Transport Properties in Nonequilibrium Steady States

2016 ◽  
Author(s):  
Wonseok Hwang ◽  
Changbong Hyeon
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Heat Dissipation ◽  
Molecular Motor ◽  
Diffusion Constant ◽  
Nonequilibrium Steady States ◽  
Directed Motion ◽  
Mean Velocity ◽  
Self Diffusion ◽  
Brownian Particles

Theoretical analysis, which maps single molecule time trajectories of a molecular motor onto unicyclic Markov processes, allows us to evaluate the heat dissipated from the motor and to elucidate its dependence on the mean velocity and diffusivity. Unlike passive Brownian particles in equilibrium, the velocity and diffusion constant of molecular motors are closely inter-related to each other. In particular, our study makes it clear that the increase of diffusivity with the heat production is a natural outcome of active particles, which is reminiscent of the recent experimental premise that the diffusion of an exothermic enzyme is enhanced by the heat released from its own catalytic turnover. Compared with freely diffusing exothermic enzymes, kinesin-1 whose dynamics is confined on one-dimensional tracks is highly efficient in transforming conformational fluctuations into a locally directed motion, thus displaying a significantly higher enhancement in diffusivity with its turnover rate. Putting molecular motors and freely diffusing enzymes on an equal footing, our study offers thermodynamic basis to understand the heat enhanced self-diffusion of exothermic enzymes.

Single-molecule mechanical study of an autonomous artificial translational molecular motor beyond bridge-burning design

Nanoscale ◽  
2021 ◽  
Author(s):  
Xinpeng Hu ◽  
Xiaodan Zhao ◽  
Iong Ying Loh ◽  
Jie Yan ◽  
Zhisong Wang
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Force Generation ◽  
Single Motor ◽  
Mechanical Study

A key capability of molecular motors is sustainable force generation by a single motor copy. Direct force characterization at single-motor level is still missing for artificial molecular motors, though long...

scholarly journals Extreme parsimony in ATP consumption by 20S complexes in the global disassembly of single SNARE complexes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changwon Kim ◽  
Min Ju Shon ◽  
Sung Hyun Kim ◽  
Gee Sung Eun ◽  
Je-Kyung Ryu ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Single Molecule ◽  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Snare Complex ◽  
Atp Binding ◽  
Attachment Protein ◽  
Receptor Complexes ◽  
Protein Receptor ◽  
Sensitive Factor

AbstractFueled by ATP hydrolysis in N-ethylmaleimide sensitive factor (NSF), the 20S complex disassembles rigid SNARE (soluble NSF attachment protein receptor) complexes in single unraveling step. This global disassembly distinguishes NSF from other molecular motors that make incremental and processive motions, but the molecular underpinnings of its remarkable energy efficiency remain largely unknown. Using multiple single-molecule methods, we found remarkable cooperativity in mechanical connection between NSF and the SNARE complex, which prevents dysfunctional 20S complexes that consume ATP without productive disassembly. We also constructed ATP hydrolysis cycle of the 20S complex, in which NSF largely shows randomness in ATP binding but switches to perfect ATP hydrolysis synchronization to induce global SNARE disassembly, minimizing ATP hydrolysis by non-20S complex-forming NSF molecules. These two mechanisms work in concert to concentrate ATP consumption into functional 20S complexes, suggesting evolutionary adaptations by the 20S complex to the energetically expensive mechanical task of SNARE complex disassembly.

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

2020 ◽  
Author(s):  
Maria Dienerowitz ◽  
Jamieson A. L. Howard ◽  
Steven D. Quinn ◽  
Frank Dienerowitz ◽  
Mark C. Leake
Keyword(s):  
Dna Replication ◽  
Single Molecule ◽  
Conformational Changes ◽  
Molecular Motors ◽  
Rational Design ◽  
Molecular Motor ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Observation Time

AbstractSingle-molecule Förster resonance energy transfer (smFRET) of molecular motors provides transformative insights into their dynamics and conformational changes both at high temporal and spatial resolution simultaneously. However, a key challenge of such FRET investigations is to observe a molecule in action for long enough without restricting its natural function. The Anti-Brownian ELectrokinetic Trap (ABEL trap) sets out to combine smFRET with molecular confinement to enable observation times of up to several seconds while removing any requirement of tethered surface attachment of the molecule in question. In addition, the ABEL trap’s inherent ability to selectively capture FRET active molecules accelerates the data acquisition process. Here we exemplify the capabilities of the ABEL trap in performing extended timescale smFRET measurements on the molecular motor Rep, which is crucial for removing protein blocks ahead of the advancing DNA replication machinery and for restarting stalled DNA replication. We are able to monitor single Rep molecules up to 6 s with 1 ms time resolution capturing multiple conformational switching events during the observation time. Here we provide a step-by-step guide for the rational design, construction and implementation of the ABEL trap for smFRET detection of Rep in vitro. We include details of how to model the electric potential at the trap site and use Hidden Markov analysis of the smFRET trajectories.

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