Abstract
The sarcomere of muscle is composed of tens of thousands of myosin motors that self-assemble into thick filaments and interact with surrounding actin-based thin filaments in a dense, near-crystalline hexagonal lattice. Together, these actin-myosin interactions enable large-scale movement and force generation, two primary attributes of muscle. Research on isolated fibres has provided considerable insight into the collective properties of muscle, but how actin-myosin interactions are coordinated in an ensemble remains poorly understood. Here, we show that artificial myosin filaments, engineered using a DNA nanotube scaffold, provide precise control over motor number, type and spacing. Using both dimeric myosin V- and myosin VI-labelled nanotubes, we find that neither myosin density nor spacing has a significant effect on the gliding speed of actin filaments. This observation supports a simple model of myosin ensembles as energy reservoirs that buffer individual stochastic events to bring about smooth, continuous motion. Furthermore, gliding speed increases with cross-bridge compliance, but is limited by Brownian effects. As a first step to reconstituting muscle motility, we demonstrate human β-cardiac myosin-driven gliding of actin filaments on DNA nanotubes.
Original language | English (US) |
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Pages (from-to) | 696-700 |
Number of pages | 5 |
Journal | Nature nanotechnology |
Volume | 10 |
Issue number | 8 |
DOIs | |
State | Published - Aug 6 2015 |
Externally published | Yes |
ASJC Scopus subject areas
- Bioengineering
- Atomic and Molecular Physics, and Optics
- Biomedical Engineering
- General Materials Science
- Condensed Matter Physics
- Electrical and Electronic Engineering