Inhibitor induced conformational changes in SARS-COV-2 papain-like protease

Area of Science:

• Biochemistry
• Structural Biology
• Computational Biology

Background:

• SARS-CoV-2 papain-like protease (PLpro) is a key viral enzyme and a target for antiviral drug development.
• Numerous crystal structures of PLpro-ligand complexes exist, providing a basis for understanding inhibitor interactions.

Purpose of the Study:

• To investigate ligand-induced conformational changes in SARS-CoV-2 PLpro using molecular dynamics (MD) simulations.
• To analyze the interactions between PLpro and specific inhibitors (GRL-0617, XR8-89, PLP_Snyder530, CPD7).

Main Methods:

• Molecular dynamics (MD) simulations of PLpro in complex with various inhibitors and an apo structure.
• Analysis of simulation data using Principal Component Analysis (PCA) and Markov State Models (MSM).

Main Results:

• Distinct conformational states of PLpro were observed in the presence and absence of ligands.
• The BL2-loop was identified as a key region contributing to inhibitor accessibility.
• MD simulations provided insights into how inhibitor substituents affect binding affinity and efficacy.

Conclusions:

• Conformational flexibility of PLpro plays a crucial role in inhibitor binding.
• Targeting specific sub-pockets, particularly near Tyr268 and Gln269, can enhance PLpro inhibition.
• Further exploration of PLpro's multiple binding sites is recommended for improved antiviral strategies.