Washington: Scientists have identified several existing compounds that block the replication of the COVID-19-causing SARS-CoV-2 virus within human cells grown in the laboratory, targeting a key viral enzyme. All of the inhibitors demonstrated potent chemical and structural interactions with viral proteins critical to the virus’s ability to proliferate, according to the study published in the journal Cell Research.
The most promising drug candidates, including the FDA-approved hepatitis C drug, boceprevir, and an investigational veterinary antiviral drug known as GC-376, target the primary protease enzyme (Mpro) SARS-CoV-2, according to researchers at the University of South Florida (USF) in the United States said.
The enzyme cuts the proteins from a long chain that the virus produces when it invades a human cell, they said. The researchers noted that without Mpro, the virus cannot replicate and infect new cells. This enzyme had already been validated as an antiviral target for SARS and MERS, both genetically similar to SARS-CoV-2, they said.
“With a rapidly emerging infectious disease like COVID-19, we don’t have time to develop new antiviral drugs from scratch,” said Yu Chen, an associate professor at USF.
“Many good drug candidates are already available as a starting point. But, with new information from studies like ours and current technology, we can help design even better drugs much faster,” Chen said.
Mpro represents an attractive target for drug development against COVID-19 due to the enzyme’s essential role in the coronavirus life cycle and the absence of a similar protease in humans, Chen noted. Since people don’t have the enzyme, drugs targeting this protein are less likely to cause side effects, he explained.
The team, which includes researchers from the University of Arizona in the United States, identified four leading drug candidates as the most powerful and specific to combat COVID-19. These are Boceprevir, a medicine to treat hepatitis C, GC-376, an investigational veterinary medicine for a deadly strain of coronavirus in cats, and calpain II and XII inhibitors, investigated in the past for cancer, neurodegenerative diseases, and others. affections, they said.
All four compounds were superior to other Mpro inhibitors previously identified as suitable for clinical evaluation to treat SARS-CoV-2, Chen added.