First structure of key COVID enzyme at human body temperature

Aug. 17, 2022
Subtle structural changes in virus's "main protease" over a range of temperatures may point to new targets for antiviral drugs.

Scientists studying a COVID-19 coronavirus enzyme at temperatures ranging from frosty to human-body warm discovered subtle structural shifts that offer clues about how the enzyme works. The findings, published in IUCrJ, the journal of the International Union of Crystallography, may inspire the design of new drugs to counteract COVID-19—and possibly help head off future coronavirus pandemics.

The protein in question is the main protease (Mpro) of SARS-CoV-2, the virus that causes COVID-19. Like all proteases, it’s an enzyme that cuts other proteins. In many viral infections, including COVID-19, infected cells initially produce a virus’s functional proteins as one single connected protein chain. Proteases cut the pieces apart so the individual proteins can make and assemble themselves into new copies of the virus. Finding a drug to disable Mpro could put the brakes on COVID-19.

To study the enzyme’s structure, the researchers used a technique called x-ray crystallography at Brookhaven Lab’s National Synchrotron Light Source II (NSLS-II). NSLS-II is a DOE Office of Science user facility that produces bright beams of x-rays. Shining those x-rays on a crystallized sample of a biological molecule can reveal the three-dimensional arrangement of atoms that make up the molecule.

Brookhaven National Laboratory release