Related Experiment Videos
Loading direction regulates the affinity of ADP for kinesin
Sotaro Uemura1, Shin'ichi Ishiwata
1Department of Physics, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Nature Structural Biology
|March 18, 2003
Summary
External load direction influences kinesin motor protein
Area of Science:
- Biophysics
- Molecular Biology
- Cellular Mechanics
Background:
- Kinesin is an ATP-driven motor protein that moves along microtubules.
- Processivity in kinesin is thought to involve alternating head binding and the ATPase cycle.
- Internal load between kinesin heads may regulate its enzymatic activity.
Purpose of the Study:
- To investigate the effect of external load direction on a single kinesin molecule's binding affinity.
- To understand the role of load in regulating the kinesin ATPase cycle and movement.
Main Methods:
- Single-molecule experiments applying controlled external loads.
- Measurement of ADP binding affinity under different loading conditions.
Main Results:
- External load in the direction of motility enhances ADP binding affinity.
- External load against the direction of motility decreases ADP binding affinity.
- Demonstrated coupling between load direction and kinesin's enzymatic activity.
Conclusions:
- External load direction is a critical factor in kinesin's function.
- Findings support the role of internal load in kinesin's unidirectional and cooperative movement.
- Provides insights into the mechanics of molecular motors.