On March 17, a study about how long the virus that causes COVID-19 survives on various surfaces was published in the New England Journal of Medicine. Led by the National Institute of Allergy and Infectious Diseases, the study found that the virus, called SARS-CoV-2, can survive on plastic and stainless steel for up to three days, on cardboard for 24 hours, and on copper for just four hours.
As soon as the study appeared online, Michael Johnson’s computer started “pinging” with incoming emails from frenzied colleagues asking, “Have you seen this?” Johnson, an expert on copper’s toxicity to pathogens, an assistant professor of immunobiology in the College of Medicine – Tucson, and a member of the BIO5 Institute, hadn’t seen it. Yet.
Johnson’s lab uses chemical compounds that deliver copper to disease-causing bacteria like Streptococcus pneumoniae and MRSA. The copper kills them. Building on the new COVID-19 findings, Johnson is now studying whether or not these same compounds could block SARS-CoV-2 from even entering human cells or hinder their ability to replicate once they do.
“There is precedence for this to work, but I think we can add a novel twist,” explained Johnson.
The compounds, he thinks, could work like this: SARS-CoV-2, like all coronaviruses, is studded with spike proteins—necessary for entry into a host cell—resembling the spikes on a crown. These proteins require metals like zinc to function, and they steal these metals from our own cells. If instead of stealing useful metals like zinc, Johnson could deliver toxic copper to the virus’s spike proteins, it could be rendered inoperable. The process is called “mismetallation,” and Johnson compares it to replacing a car’s steering wheel with bike handles and its ignition with the pull cord on a lawnmower.
“Eventually, the car is going to become undriveable,” he said.
Just one problem. “I’m not a virologist—not even on the weekends,” he quipped.
So Johnson enlisted the help of Koenraad Van Doorslaer, an assistant professor of immunobiology and expert virologist in the College of Agriculture and Life Sciences. Wei Wang, a professor of pharmacology and toxicology who creates the compounds they’ll be testing, and Elisa Tomat, an associate professor of chemistry and biochemistry who is an expert on metal ionophores, are advising Johnson and Van Doorslaer as they experiment.
“Making great things happen in science requires one fundamental thing, and that’s the spirit of collaboration,” said Johnson. “We all have different expertise, but we come together for a common purpose and we create something better than the sum of our parts.”
Johnson noted that he and Van Doorslaer are not using SARS-CoV-2 samples to conduct their experiments.
“We are using a virus that mimics the SARS-CoV-2 virus, but that will not cause disease. This is a powerful and safe way to identify drugs that could impact COVID-19,” said Van Doorslaer, who teaches in the School of Animal and Comparative Biomedical Sciences. They’re also using a different, seasonal coronavirus that is not as dangerous as SARS-CoV-2 to test copper’s effect against other components of the virus.
“Ultimately, if we’re successful with our preliminary vetting, we will move forward with testing these compounds directly on SARS-CoV-2,” said Johnson.
If copper proves effective in the cellular battle against COVID-19, physicians could use already existing therapeutics in tandem with copper to deliver an extra punch of toxicity to the virus. “That’s what makes this an experiment worth doing,” said Johnson.