scholarly journals Kinetic analysis methods applied to single motor protein trajectories

2018 ◽  
Vol 20 (27) ◽  
pp. 18775-18781
Author(s):  
A. L. Nord ◽  
A. F. Pols ◽  
M. Depken ◽  
F. Pedaci
Keyword(s):  
Kinetic Analysis ◽  
Molecular Motors ◽  
Motor Protein ◽  
Electrical Energy ◽  
Mechanical Displacement ◽  
Single Motor ◽  
Analysis Methods

Molecular motors convert chemical or electrical energy into mechanical displacement, either linear or rotary.

scholarly journals Correction: Kinetic analysis methods applied to single motor protein trajectories

2019 ◽  
Vol 21 (22) ◽  
pp. 12044-12044
Author(s):  
A. L. Nord ◽  
A. F. Pols ◽  
M. Depken ◽  
F. Pedaci
Keyword(s):  
Kinetic Analysis ◽  
Motor Protein ◽  
Chem Phys ◽  
Single Motor ◽  
Analysis Methods ◽  
Phys Chem Chem Phys

Correction for ‘Kinetic analysis methods applied to single motor protein trajectories’ by A. L. Nord et al., Phys. Chem. Chem. Phys., 2018, 20, 18775–18781.

scholarly journals Kinetic analysis methods applied to single motor protein trajectories

2018 ◽  
Author(s):  
A L Nord ◽  
A F Pols ◽  
M Depken ◽  
F Pedaci
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
Thermal Noise ◽  
Molecular Motor ◽  
Electrical Energy ◽  
Flagellar Motor ◽  
Step Size ◽  
Analysis Methods ◽  
Chemical States ◽  
Rate Limiting

Molecular motors convert chemical or electrical energy into mechanical displacement, either linear or rotary. Under ideal circumstances, single-molecule measurements can spatially and temporally resolve individual steps of the motor, revealing important properties of the underlying mechanochemical process. Unfortunately, steps are often hard to resolve, as they are masked by thermal noise. In such cases, details of the mechanochemistry can nonetheless be recovered by analyzing the fluctuations in the recorded traces. Here, we expand upon existing statistical analysis methods, providing two new avenues to extract the motor step size, the effective number of rate-limiting chemical states per translocation step, and the compliance of the link between the motor position and the probe particle. We first demonstrate the power and limitations of these methods using simulated molecular motor trajectories, and we then apply these methods to experimental data of kinesin, the bacterial flagellar motor, and F1-ATPase.

scholarly journals Speed-detachment tradeoff and its effect on track bound transport of single motor protein

2018 ◽  
Author(s):  
Mohd Suhail Rizvi
Keyword(s):  
Experimental Data ◽  
Random Walk ◽  
Power Law ◽  
Average Distance ◽  
Motor Protein ◽  
Fixed Duration ◽  
Biological Cells ◽  
Single Motor ◽  
Stochastic Nature ◽  
Time Required

AbstractThe transportation of the cargoes in biological cells is primarily driven by the motor proteins on filamentous protein tracks. The stochastic nature of the motion of motor protein often leads to its spontaneous detachment from the track. Using the available experimental data, we demonstrate a tradeoff between the speed of the motor and its rate of spontaneous detachment from the track. Further, it is also shown that this speed-detachment relation follows a power law where its exponent dictates the nature of the motor protein processivity. We utilize this information to study the motion of motor protein on track using a random-walk model. We obtain the average distance travelled in fixed duration and average time required for covering a given distance by the motor protein. These analyses reveal non-monotonic dependence of the motor protein speed on its transport and, therefore, optimal motor speeds can be identified for the time and distance controlled conditions.

scholarly journals Imaging the Cannabinoid CB1 Receptor in Humans with [11C] OMAR: Assessment of Kinetic Analysis Methods, Test–Retest Reproducibility, and Gender Differences

2015 ◽  
Vol 35 (8) ◽  
pp. 1313-1322 ◽  
Author(s):  
Marc D Normandin ◽  
Ming-Qiang Zheng ◽  
Kuo-Shyan Lin ◽  
N Scott Mason ◽  
Shu-Fei Lin ◽  
...  
Keyword(s):  
Gender Differences ◽  
Kinetic Analysis ◽  
Human Subjects ◽  
Intraclass Correlation ◽  
Volume Of Distribution ◽  
Absolute Deviation ◽  
Retest Reliability ◽  
Analysis Methods ◽  
Test Retest Reliability

The Radiotracer [11C]OMAR was developed for positron emission tomography (PET) imaging of cannabinoid type-1 receptors (CB1R). The objectives of the present study were to evaluate kinetic analysis methods, determine test–retest reliability, and assess gender differences in receptor availability. Dynamic PET data were acquired in 10 human subjects, and analyzed with one-tissue (1T) and two-tissue (2T) compartment models and by the Logan and multilinear analysis (MA1) methods to estimate regional volume of distribution ( VT). The 2T model inclusive of a vascular component (2TV) and MA1 were the preferred techniques. Test–retest reliability of VT was good (mean absolute deviation ~ 9%; intraclass correlation coefficient ~ 0.7). Tracer parent fraction in plasma was lower in women ( P < 0.0001). Cerebral uptake normalized by body weight and injected dose was higher in men by 17% ( P < 0.0001), but VT was significantly greater in women by 23% ( P < 0.0001). These findings show that [11C]OMAR binding can be reliably quantified by the 2T model or MA1 method and demonstrate the utility of this tracer for in vivo imaging of CB1R. In addition, results from the present study indicate that gender difference in receptor binding should be taken into consideration when [11C]OMAR is used to quantify CB1R availability in neuropsychiatric disorders.

scholarly journals COOPERATIVE TRANSPORT BY SMALL TEAMS OF MOLECULAR MOTORS

2006 ◽  
Vol 01 (04) ◽  
pp. 353-361 ◽  
Author(s):  
STEFAN KLUMPP ◽  
MELANIE J. I. MÜLLER ◽  
REINHARD LIPOWSKY
Keyword(s):  
Molecular Motors ◽  
Single Motor ◽  
Directed Transport ◽  
Cargo Transport ◽  
Cooperative Transport

Molecular motors power directed transport of cargoes within cells. Even if a single motor is sufficient to transport a cargo, motors often cooperate in small teams. We discuss the cooperative cargo transport by several motors theoretically and explore some of its properties. In particular we emphasize how motor teams can drag cargoes through a viscous environment.

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...

Expression of a minus-end-directed motor protein induces Sf9 cells to form axon-like processes with uniform microtubule polarity orientation

1997 ◽  
Vol 110 (19) ◽  
pp. 2373-2380
Author(s):  
D.J. Sharp ◽  
R. Kuriyama ◽  
R. Essner ◽  
P.W. Baas
Keyword(s):  
Molecular Motors ◽  
Mitotic Spindle ◽  
Morphological Characteristics ◽  
Motor Protein ◽  
Motor Domain ◽  
Sf9 Cells ◽  
Atp Binding Site ◽  
Microtubule Polarity ◽  
Process Formation ◽  
Induce Process

Neurons extend two types of processes with distinct morphologies and patterns of microtubule polarity orientation. Axons are thin cylindrical processes containing microtubules that are uniformly oriented with their plus-ends-distal to the cell body while dendrites are stout tapering processes that contain nonuniformly oriented microtubules. We have proposed that these distinct microtubule patterns are established by molecular motors that transport microtubules into each type of process with the appropriate orientation. To test the feasibility of this proposal, we have embarked on a series of studies involving the expression of vertebrate motors in insect Sf9 cells. We previously focused on a kinesin-related protein termed CHO1/MKLP1, which localizes to the midzone of the mitotic spindle, and which has been shown to have the appropriate properties to transport microtubules of opposite orientation relative to one another. Expression of a fragment of CHO1/MKLP1 containing its motor domain induces Sf9 cells to extend processes with a stout tapering morphology and a nonuniform microtubule polarity pattern similar to dendrites. Here we focus on a minus-end-directed kinesin-related motor protein termed CHO2, which localizes to the non-overlapping regions of the mitotic spindle, and which has been shown to have the appropriate properties to transport microtubules with plus-ends-leading. Sf9 cells induced to express a fragment of CHO2 containing its motor domain extend processes with a long cylindrical morphology and a uniformly plus-end-distal microtubule polarity pattern similar to axons. These results show that motor proteins have the capacity to organize distinct patterns of microtubule polarity orientation during process outgrowth, and that these patterns are intimately related to the unique morphological characteristics of the processes. Moreover, mutation of three amino acids corresponding to the ATP binding site necessary for motor function suppresses the capacity of the CHO2 fragment to induce process formation and microtubule reorganization, indicating that at least in the case of CHO2, the transport properties of the motor are essential for it to elicit these effects.

scholarly journals Poleward transport of Eg5 by dynein–dynactin in Xenopus laevis egg extract spindles

2008 ◽  
Vol 182 (4) ◽  
pp. 715-726 ◽  
Author(s):  
Marianne Uteng ◽  
Christian Hentrich ◽  
Kota Miura ◽  
Peter Bieling ◽  
Thomas Surrey
Keyword(s):  
Cell Division ◽  
Xenopus Laevis ◽  
Molecular Motors ◽  
Motor Proteins ◽  
Motor Protein ◽  
Spindle Assembly ◽  
Cross Linking ◽  
Motor Movement ◽  
Spindle Poles ◽  
Egg Extract

Molecular motors are required for spindle assembly and maintenance during cell division. How motors move and interact inside spindles is unknown. Using photoactivation and photobleaching, we measure mitotic motor movement inside a dynamic spindle. We find that dynein–dynactin transports the essential motor Eg5 toward the spindle poles in Xenopus laevis egg extract spindles, revealing a direct interplay between two motors of opposite directionality. This transport occurs throughout the spindle except at the very spindle center and at the spindle poles, where Eg5 remains stationary. The variation of Eg5 dynamics with its position in the spindle is indicative of position-dependent functions of this motor protein. Our results suggest that Eg5 drives microtubule flux by antiparallel microtubule sliding in the spindle center, whereas the dynein-dependent concentration of Eg5 outside the spindle center could contribute to parallel microtubule cross-linking. These results emphasize the importance of spatially differentiated functions of motor proteins and contribute to our understanding of spindle organization.

Sign in / Sign up

Export Citation Format

Share Document