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Updated: Mar 16, 2026
08:57
Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
Published on: February 4, 2021
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Myosin V is a biological Brownian machine.
Keisuke Fujita1, Mitsuhiro Iwaki2
1Quantitative Biology Center, RIKEN, Suita, Osaka 565-0874, Japan.
Biophysics (Nagoya-Shi, Japan)
|August 6, 2016
Summary
The Brownian search-and-catch mechanism is the main driver of myosin V force generation, doing more work than the lever-arm swing. This finding challenges previous models of myosin V function.
Area of Science:
- Biophysics
- Molecular Motors
- Cellular Transport
Background:
- Myosin V is a molecular motor that transports vesicles along actin filaments.
- Force generation in myosin V involves a lever-arm swing and a Brownian search-and-catch mechanism.
Purpose of the Study:
- To quantify the energetic contributions of the lever-arm swing and Brownian search-and-catch mechanisms in myosin V force generation.
- To re-evaluate the dominant model of myosin V force production.
Main Methods:
- Utilized a combined system of optical tweezers and DNA nanotechnology.
- Measured the work output of myosin V at near stall force.
Main Results:
- The Brownian search-and-catch mechanism provided 13 kBT of work, significantly more than the 3 kBT from the lever-arm swing.
- Demonstrated that Brownian search-and-catch is the energetically dominant process near stall force.
Conclusions:
- The Brownian search-and-catch mechanism plays a more critical role in myosin V force generation than previously assumed.
- This study necessitates a reconsideration of the lever-arm swinging model as the primary work-producing process in myosin V.
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