While vaccines and Covid-19 medications have mitigated the disease's impact and contained the pandemic, the constant mutation of the virus poses an ongoing threat.
SARS-CoV-2, responsible for the most devastating pandemic of the 21st century, affected over 700 million people and claimed nearly seven million lives.
A team led by University of Göttingen researchers discovered crucial "protective switches" within the virus, shielding it from immune attacks, as detailed in their publication in Nature Communications.
In a molecular arms race, the virus evolves strategies to effectively infect human cells and evade the immune system.
The virus utilizes this protease to facilitate its replication by cutting out other virus proteins in infected cells, employing the amino acid cysteine for this process.
Within the virus's main "protease," a pivotal protein targeted by the primary Covid-19 drug Paxlovid®, the researchers identified two previously unknown chemical protective switches.
The virus achieves this protection by forming a stabilizing disulfide bond between two cysteine atoms and employing a bridge called SONOS to prevent radical damage to its three-dimensional structure.
The researchers found that the protective switches shield the protease from the immune system's oxygen radical bombardment, crucial for fighting viruses.
This groundbreaking study, funded by the Covid-19 Research Network Lower Saxony (COFONI) and the German Research Foundation (DFG), involved interdisciplinary collaboration across multiple institutions.
Despite the elegance of the virus's defense mechanism, the researchers delved further by searching for molecules that could precisely bind to these "protective switches," inhibiting the virus's main protease.