Artificial microtubules burst with energy

Abstract

Among the multitude of biological machines that nature employs to keep the cell operational, molecular motor proteins are certainly among the most captivating. These proteins convert chemical energy into mechanical work and drive most forms of motion (1). Cytoplasmic motors, for example, are proteins that move along a track and can transport cargo or induce muscle contraction. Beside these types of linear motion, rotary motion is ubiquitous. It occurs, for example, in flagella, which propel bacteria, or in ATP synthase, the protein that creates ATP. Alternatively, polymerization motors, such as actin filaments or microtubules, generate force by their assembly or disassembly. To understand the dynamics of the living cell, as well as to create increasingly complex artificial systems, chemists strive to construct artificial molecular motors and machines. In PNAS, Fredy et al. (2) present an innovative design that combines molecular motion with supramolecular chemistry to build a light-powered self-assembled machine in which energy is accumulated and released. This induces a mechanical effect that mimics the pulling force of microtubule disassembly. Synthetic molecular machines of increasing sophistication have been built and studied for several decades (3). Analogous to molecular motors found in nature, they are defined as molecules that can convert an energy input, typically in the form of chemical fuel or light, into translational or rotational motion. To harvest this output for mechanical work remains a fundamental challenge as molecular machines usually operate in solution. At the molecular scale, Brownian movement and viscous forces dominate, while the influence of gravity and inertia is negligible. Any force generated by a … [↵][1]1To whom correspondence should be addressed. Email: b.l.feringa{at}rug.nl. [1]: #xref-corresp-1-1