Scientists have built the smallest antenna ever – just five nanometers long. Unlike its much larger counterparts that we all know, this tiny thing isn’t made to transmit radio waves, but to glean the secrets of ever-changing proteins.
The nanoantenna is made up of DNA, molecules carrying genetic instructions about 20,000 times smaller than a human hair. It is also fluorescent, which means it uses light signals to record and report information.
And these light signals can be used to study the movement and change of proteins in real time.
Part of the innovation with this particular antenna is how the receptor part of it is also used to detect the molecular surface of the protein it is studying. This results in a distinct signal when the protein performs its biological function.
“Like a two-way radio that can both receive and transmit radio waves, the fluorescent nanoantenna receives light in a color, or wavelength, and according to the movement of the proteins it detects, then retransmits the light in a another color that we can detect, ”explains chemist Alexis Vallée-Bélisle, from the University of Montreal (UdeM) in Canada.
Specifically, the job of the antenna is to measure structural changes in proteins over time. Proteins are large, complex molecules that do all kinds of essential tasks in the body, from supporting the immune system to regulating organ function.
However, as proteins rush to do their job, they undergo constant structural changes, moving from state to state in a very complex process that scientists call protein dynamics. And we don’t really have the right tools to track the dynamics of these proteins in action.
“The experimental study of transient states of proteins remains a major challenge as high structural resolution techniques, including nuclear magnetic resonance and x-ray crystallography, often cannot be directly applied to study short-lived protein states. “, explains the team in their article.
The latest DNA synthesis technology – around 40 years of development – is capable of producing bespoke nanostructures of various lengths and flexibilities, optimized to perform their required functions.
One of the advantages of this very small DNA antenna over other analytical techniques is that it is able to capture protein states of very short duration. According to the researchers, this means that there are many potential applications here, both in biochemistry and in nanotechnology in general.
“For example, we were able to detect, in real time and for the first time, the function of the enzyme alkaline phosphatase with a variety of biological molecules and drugs,” explains chemist Scott Harroun of UdeM. “This enzyme has been implicated in many diseases, including various cancers and intestinal inflammation.”
While exploring the “universality” of their design, the team successfully tested their antenna with three different model proteins – streptavidin, alkaline phosphatase, and protein G – but there is potentially a lot more to come, and one of the few. advantages of the new antenna is its versatility.
“Nanoantennas can be used to monitor distinct biomolecular mechanisms in real time, including small and large conformational changes – in principle, any event that can affect the fluorescence emission of the dye,” the team wrote in their paper.
DNA is becoming increasingly popular as a building block that we can synthesize and manipulate to create nanostructures like the antenna in this study. DNA chemistry is relatively simple to program and easy to use once programmed.
Researchers are now looking to create a commercial startup so that nanoantenna technology can be practically packaged and used by others, whether they be pharmaceutical organizations or other research teams.
“Perhaps what excites us most is the realization that many laboratories around the world, equipped with a conventional spectrofluorometer, could easily use these nanoantennas to study their favorite protein, for example to identify new drugs or develop new ones. nanotechnologies, ”says Vallée -Bélisle.
The research was published in Natural methods.