Chemists at New York University and Harvard University have created a bipedal, autonomous DNA "walker" that can mimic a cell's transportation system.
The device, which marks a step toward more complex synthetic molecular motor systems, is described in the most recent issue of the journal Science. For a video demonstration of the walker, go to http://www.nyu.edu/public.affairs/videos/qtime/biped_movie.mov.
Two fundamental components of life's building blocks are DNA, which encodes instructions for making proteins, and motor proteins, such as kinesin, which are part of a cell's transportation system. In nature, single strands of DNA—each containing four molecules, or bases, attached to backbone—self-assemble to form a double helix when their bases match up. Kinesin is a molecular motor that carries various cargoes from one place in the cell to another. Scientists have sought to re-create this capability by building DNA walkers.
Earlier versions of walkers, which move along a track of DNA, did not function autonomously, thereby requiring intervention at each step. A challenge these previous devices faced was coordinating the movement of the walker's legs so they could move in a synchronized fashion without falling off the track.
To create a walker that could move on its own, the NYU and Harvard researchers employed two DNA "fuel strands" (purple and green in the above video). These fuel strands push the walker (blue) along a track of DNA, thereby allowing the walker and the fuel strands to function as a catalytic unit.
The forward progress of the system is driven by the fact that more base pairs are formed every step—a process that creates the energy necessary for movement. As the walker moves along the DNA track, it forms base pairs. Simultaneously, the fuel strands move the walker along by binding to the track and then releasing the walker's legs, thereby allowing the walker to take "steps".
The track's length is 49 nanometers—if the track was one meter long, an actual meter, enlarged proportionally, would be the approximate diameter of the earth.
The walker was created in the laboratory of NYU Chemistry Professor Nadrian Seeman, one of the article's co-authors. The paper's other authors were Tosan Omabegho, a doctoral candidate at Harvard's School of Engineering and Applied Sciences, and Ruojie Sha, a senior research associate in the NYU Chemistry Department.
James Devitt | EurekAlert!
Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory
‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Materials Sciences
11.12.2017 | Earth Sciences