The protease is not only heart-shaped, but works as the “heart” of the new coronavirus, according to newly published research.
A team from the Oak Ridge National Laboratory (ORNL), in the United States, performed the first X-ray measurements at room temperature of the main protease of Sars-CoV-2, which allows the replication of the new coronavirus. In an article published this week in the journal Nature Communications, the researchers released images of the enzyme, which resembles a heart.
“The protein is shaped like a valentine’s heart, but it really is the heart of the virus that allows it to replicate and spread,” explained Andrey Kovalevsky, co-author of the study, in a statement. “If you inhibit the protease and stop the heart, the virus cannot produce the proteins that are essential for its replication. That’s why the protease is considered such an important drug target.”
Building a complete model of the protein requires identifying each element within the structure and how they are organized – and X-rays are ideal for detecting heavy elements, such as carbon atoms, nitrogen, and oxygen. To extend the lifetime of the samples and measure them at room temperature, the researchers grew the molecules in cryogenic crystals and used an X-ray machine with a less intense beam.
“This is the first time the structure of this enzyme has been measured at room temperature,” said Kovalevsky. “[This] is significant because it’s near the physiological temperature where the cells operate.”
According to the scientists, the protease consists of chains of amino acids with a repetitive pattern of nitrogen-carbon-carbon atoms that form their “backbone”. In addition, side groups of particles extend from each of the carbon atoms in this “central skeleton”.
This structure is slightly different from that observed in previous analyzes, in which the protease was frozen. The experts intend to continue studying the molecule, now focusing on its hydrogen molecules, to create a more credible 3D model of the enzyme.
According to the team, studies of this type are important for the development of treatments that focus on proteases. “Our room temperature data is being used to build a more accurate model for those simulations and improve drug design activities,” said Leighton Coates, who also participated in the research.