Chemists create nanomachines by breaking them apart

To explore this question, his doctoral student Dominic Lauzon, had the “destructive” idea of breaking up some nanomachines to see if they could be reassembled. To do so, he made artificial DNA-based nanomachines that could be “destroyed” by breaking them up.

Dominic Lauzon and Alexis Vallée-Bélisle have discovered that the function of molecular nanomachines can evolve efficiently if broken into multiple components. The image illustrates how making nanomachines using a single green component (top) leads to a single-function structure. In contrast, fabricating similar nanomachines using three components (blue, orange, and green) creates functional structures with new properties, such as greater or lesser sensitivity – i.e., cooperative or anticooperative – and molecular clock function. Image credit: Caitlin Monney

“DNA is a remarkable molecule that offers simple, programmable and easy-to-use chemistry,” said Lauzon, the study’s first author.

“We believed that DNA-based nanomachines could help answer fundamental questions about the creation and evolution of natural and human-made nanomachines.”

Lauzon and Vallée-Bélisle spent years performing the experimental validations.

They were able to demonstrate that nanomachines could easily withstand fragmentation, but more importantly, that such a destructive event allowed for the creation of various novel functionalities, including different sensitivity levels towards variation in component concentration, temperature and mutations.

The researchers found that these functionalities could arise simply by controlling the concentration of each individual component.

For example, when cutting a nanomachine in three components, nanomachines were found to activate more sensitively at high concentration of components.

In contrast, at low concentration of components, nanomachines could be programmed to activate or deactivate at specific moment in time or to simply inhibit their function.

“Overall, these novel functionalities were created  by simply cutting up, or destroying, the structure of an existing nanomachine,” said Lauzon. “These functionalities could drastically improve human-based nanotechnologies such as sensors, drug carriers and even molecular computers”.

Evolving new functionalities

Just as Picasso typically destroyed dozens of unfinished works to create his famous artworks, muscles need to break down to get stronger, and innovative new companies are born by eliminating older competitors from the market, nanoscale machines can evolve new functionalities by being taken apart.

Unlike common machines like cell phones, televisions and cars, which combine components using screws and bolts, glue, solder or electronics, “nanomachines rely on thousands of weak dynamic intermolecular forces that can spontaneously reform, enabling broken nanomachines to re-assemble,” said Vallée-Bélisle.

In addition to providing nanotechnology researchers with a simple design strategy to create the next generation of nanomachines, the UdeM team’s findings also shed light on how natural molecular nanomachines may have evolved.

“Biologists have recently discovered that about 20 per cent of biological nanomachines may have evolved through the fragmentation of their genes,” said Vallée-Bélisle. “With our results, biologists now have a rational basis for understanding how the fragmentation of these ancestral proteins could have created new molecular functionalities for life on Earth.”

Source: University of Montreal