Novel Protein-Based Sensors Rapidly Detect Coronavirus Antibodies

A new method has been developed by researchers to detect the proteins that constitute the pandemic coronavirus, along with its antibodies. They created protein-based biosensors that glow on combining with components of the virus or particular COVID-19 antibodies.

This discovery could allow quicker and more extensive testing in the forthcoming days. The study has been published in the Nature journal.

At present, a majority of the medical labs depend on a method known as RT-PCR for the diagnosis of coronavirus infection. The method involves amplifying genetic material from the virus so that it can be viewed and needs specialized equipment and staff. Moreover, it consumes laboratory supplies that are currently in high demand worldwide. Supply-chain shortages have decelerated COVID-19 test findings in the United States and other nations.

A research team under the guidance of David Baker, professor of biochemistry and director of the Institute for Protein Design at University of Washington (UW) Medicine, made use of computers to design new biosensors, in an attempt to directly detect coronavirus in samples from patients without the need for genetic amplification.

Such protein-based devices identify particular molecules on the surface of the virus, attach to them, and further emit light via a biochemical reaction.

Antibody testing has the potential to disclose if a person has had a COVID-19 infection earlier. It is being applied to monitor the pandemic spread, but it also needs complex laboratory supplies and equipment.

The same research group of UW scientists made biosensors that glow when combined with COVID-19 antibodies. They demonstrated that such sensors do not respond to other antibodies that may also exist in the blood, such as those that target other viruses. This sensitivity is crucial to prevent false-positive test results.

We have shown in the lab that these new sensors can readily detect virus proteins or antibodies in simulated nasal fluid or donated serum. Our next goal is to ensure they can be used reliably in a diagnostic setting. This work illustrates the power of de novo protein design to create molecular devices from scratch with new and useful functions.

David Baker, Professor of Biochemistry and Director, Institute for Protein Design, School of Medicine, University of Washington

Apart from COVID-19, the researchers also demonstrated that similar biosensors could be developed to detect medically relevant human proteins like Bcl-2 (which is of clinical significance in lymphoma and a few other types of cancer) and Her2 (a biomarker and therapy target for certain forms of breast cancer), as well as bacterial antibodies and toxin that target hepatitis B virus.

This study was financially supported by the National Institutes of Health, Howard Hughes Medical Institute, Air Force Office of Scientific Research, The Audacious Project, Eric and Wendy Schmidt by recommendation of the Schmidt Futures, Washington Research Foundation, and Nordstrom Barrier Fund.

The study was also supported by the Open Philanthropy Project, LG Yonam Foundation, BK21 PLUS project of Korea, United World Antiviral Research Network (UWARN), which is one of the Centers Researching Emerging Infectious Diseases, Gree Real Estate, and “la Caixa” Foundation.

Journal Reference:

Quijano-Rubio, A., et al. (2021) De novo design of modular and tunable protein biosensors. Nature. doi.org/10.1038/s41586-021-03258-z.