UC Davis Researchers Adapt Nanotech to Catch Coronavirus

Professor Michael Toney in his chemistry lab
Professor Michael Toney (right) and postdoc Matthew Hoag in the Department of Chemistry. Photo credit: Hector Amezcua

When COVID-19 reached pandemic level in March, two researchers in the UC Davis College of Letters and Science rapidly switched their focus to combatting the new coronavirus. 

The two professors, Daniel Cox and Michael Toney, are inventors of a patented technique for growing nanoscale protein polymer fibrils. The fibrils act like scaffolds, and can be manipulated to create new materials with specific functions. Cox and Toney developed the technology for applications such as nanowires and biomaterials. Now their goal is to capture the SARS-CoV-2 virus that causes COVID-19. 

“We’re motivated by the chance to make a difference in protecting people until an effective vaccine is developed,” said Cox, a professor of physics. 

Platform to help diagnose the new coronavirus

Cox and Toney’s prototype centers on protein polymer fibrils engineered to carry a piece of ACE2 protein. Found on the surface of human cells, the ACE2 protein is the gateway into cells for the SARS-CoV-2 virus. They are testing whether the fibrils will lock onto the SARS-CoV-2 “spike” protein, which coats the outside of the virus. 

The researchers are working with amyloid proteins, which naturally self-assemble (or polymerize) into fibrils. To manufacture the amyloid proteins, Toney, a professor of chemistry, designed synthetic genes and inserted the genes into bacteria. After growing and harvesting the bacteria and isolating the proteins, the purified protein molecules, called monomers, were incubated for several days to encourage fibrils to form. The monomers knit together like Velcro, forming fibrils about 10 micrometers long with the spike-binding piece of ACE2 protein attached along their length. 

“Because each monomer has the spike-binding segment of ACE2, these long polymers should serve as really efficient grabbers of the virus,” Toney said. “This is an effect called avidity.”

Rapid and sensitive COVID-19 detection

The team hopes their work will contribute to the development of simple, rapid tests to detect the SARS-CoV-2 virus. For example, the polymer fibrils could replace antibodies in existing tests, and boost sensitivity and specificity by capturing more viral proteins and concentrating those proteins for testing, Cox said. The technology could also be used to coat personal protective equipment, such as fabric masks, and boost their effectiveness against the virus, he said.

If the prototype polymers are a success, Cox and Toney will need a pharmaceutical partner to manufacture the fibrils and test them in clinical trials. And before any test is deployed, it must be approved by the Food and Drug Administration.

The researchers first developed the protein platform in 2012 with seed funding from the UC Davis Research Investments in the Sciences and Engineering (RISE) program. The University of California holds a patent on the protein manufacturing process. Cox and Toney are also co-founders of Protein Architects Inc., launched in 2015 to further develop the technology. 

Becky Oskin, content strategist in the UC Davis College of Letters and Science