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Updated: May 31, 2026
07:47
Directly Measuring Forces Within Reconstituted Active Microtubule Bundles
Published on: May 10, 2022
Force-velocity relationship for multiple kinesin motors pulling a magnetic bead
Todd L Fallesen1, Jed C Macosko, G Holzwarth
1Department of Physics, Wake Forest University, PO Box 7507, Winston-Salem, NC 27109, USA.
European Biophysics Journal : EBJ
|July 8, 2011
Summary
Multiple kinesin motors move microtubules similarly to single motors under load. At higher forces per motor, their velocity distribution shows distinct modes, supporting theoretical models of multimotor transport.
Area of Science:
- Biophysics
- Molecular Motor Dynamics
- Cellular Mechanics
Background:
- Single kinesin motor velocity against load is established.
- Multimotor kinesin transport mechanics remain poorly understood.
Purpose of the Study:
- Investigate the force-velocity relationship of multiple kinesin-1 motors.
- Understand how multiple motors coordinate to overcome loads.
Main Methods:
- Gliding assays using 3-7 Drosophila kinesin-1 motors.
- Microtubule movement measured against magnetic field-generated loads (0-31 pN).
- Saturating ATP conditions.
Main Results:
- Force-velocity relationship for multiple motors mirrors single motor behavior when force is normalized by motor number.
- Velocity distributions show single mode at low load, indicating rapid motor number fluctuations.
- At 2.5-4.7 pN/motor load, lower velocity modes emerge.
Conclusions:
- Multiple kinesin motors exhibit load-sharing behavior consistent with a minimal model.
- Observed velocity distributions support the Klumpp-Lipowsky model for multimotor transport.
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