19F NMR Reveals Hidden Bound-State Dynamics of SARS-CoV-2 3CLpro-Inhibitor Complexes, Guiding Next-Generation Antiviral Design
核心洞察
Researchers used fluorine-19 nuclear magnetic resonance (19F NMR) to uncover previously unknown slow dynamics in how nirmatrelvir-based 3CLpro inhibitors bind the SARS-CoV-2 (搜索) main protease.
The 3CLpro-inhibitor complexes slowly convert back and forth between two states, dynamics invisible to earlier techniques that suppress protein motion.
Understanding these bound states could help chemists modulate drug binding affinity to design more potent antivirals, with relevance extending beyond coronaviruses.
The 3C-like protease (3CLpro) (搜索) enzyme is vital for viruses' ability to replicate, including coronaviruses. Some antiviral drugs work by inhibiting 3CLpro — for example, this is how nirmatrelvir/ritonavir (Paxlovid) (搜索) targets the COVID-19 (搜索) virus. To better understand the way these drugs work, De Falco et al. studied how nirmatrelvir 3CLpro-inhibitors bind with the enzyme 3CLpro, uncovering previously unknown dynamics.
"Designing new drugs when the old ones don't work anymore is based on what we know about how the drug binds to its target, and how we could modify that design to make better drugs," said author Theresa Ramelot.
Hidden Dynamics Revealed by 19F NMR
Using fluorine-19 nuclear magnetic resonance (19F NMR), the researchers found that 3CLpro-inhibitor complexes slowly convert back and forth between two states, changing how they interact with 3CLpro. These dynamics were invisible to previous techniques, which study proteins in environments that suppress their motion.
Though the atomic nature of the motion is still poorly understood, the dynamics are fundamental to the way the proteins work. By tapping into these states, chemists can modulate a drug's binding affinity to make more potent medications.
Broad Applicability Beyond Coronaviruses
Because 3CLpro-like enzymes exist in many different viruses, how they bind and what inhibits them is widely applicable beyond just coronaviruses. "These are molecules that are actually being used in people," said author Gaetano Montelione. "Millions of doses of this drug are being taken."
The researchers do not know whether these dynamics play a role in drug safety, but they noted the importance of gathering as full a picture of 3CLpro systems as possible. Their work also demonstrates 19F NMR's utility in studying slow drug-enzyme interactions, which can be used to monitor and improve other antiviral medications.