Research groups at Hokkaido University, Kansai University, and Tokyo Institute of Technology have succeeded for the first time in the world in developing a molecular artificial muscle that directly converts chemical energy into mechanical energy by combining motor proteins and DNA origami.
Motor proteins are nanometer-sized molecular machines that convert chemical energy into mechanical work. Myosin that moves on actin and kinesin and dynein that move on microtubules are known.The development of biotechnology has made it possible to synthesize motor proteins, and because of its high energy conversion efficiency and specific output characteristics, it is expected to be a power source for micromachines and molecular robots.However, it has never been possible to orderly assemble nanometer-sized motor proteins to a visible size.
In this research, DNA origami structure (structure by DNA folding technology [origami]) is made by DNA nanotechnology, and DNA-modified microtubes are made by biotechnology.When these were mixed, an "aster structure" was formed in which microtubules were assembled radially.When kinesin (quaternized with streptavidin protein) was added to this, the aster structures were further aggregated to form a millimeter-sized network structure.Finally, when adenosine triphosphate (ATP) was added, a rapid contraction movement up to 1/40 of the original size was observed.This contractile system is a "molecular artificial muscle" that imitates the smooth muscle cells that move the heart and internal organs of the human body.
As a result, a power system with a size of millimeters to centimeters driven by chemical energy will be realized, and it is expected to be a power source for medical microrobots and insect-type drones in the future.
Paper information:[Nano Letters] Artificial Smooth Muscle Model Composed of Hierarchically Ordered Microtubule Asters Mediated by DNA Origami Nanostructures
