The molecular mechanism of non-covalent inhibitor WU-04 targeting SARS-CoV-2 3CLpro and computational evaluation of its effectiveness against mainstream coronaviruses

• Published in: Physical chemistry chemical physics : PCCP 2023-09, Vol.25 (35), p.23555-23567
• Main Authors: Wu, Jianhua, Zhang, Hong-Xing, Zhang, Jilong
• Format: Article
• Language: English
• Subjects: Binding; Bonding strength; Covalence; Energy value; Hydrogen bonds; Hydrophobicity; Inhibitors; Molecular dynamics; Pharmacology; Proteins; Residues; Severe acute respiratory syndrome coronavirus 2; Viral diseases
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d3cp03828a

There is an urgent need for highly effective therapeutic agents to interrupt the continued spread of SARS-CoV-2. As a pivotal protease in the replication process of coronaviruses, the 3CLpro protein is considered as a potential target of drug development to stop the spread and infection of the virus. In this work, molecular dynamics (MD) simulations were used to elucidate the molecular mechanism of a novel and highly effective non-covalent inhibitor, WU-04, targeting the SARS-CoV-2 3CLpro protein. The difference in dynamic behavior between the apo -3CLpro and the holo -3CLpro systems suggests that the presence of WU-04 inhibits the motion amplitude of the 3CLpro protein relative to the apo -3CLpro system, thus maintaining a stable conformational binding state. The energy calculations and interaction analysis show that the hot-spot residues Q189, M165, M49, E166, and H41 and the warm-spot residues H163 and C145 have a strong binding capacity to WU-04 by forming multiple hydrogen bonds and hydrophobic interactions, which stabilizes the binding of the inhibitor. After that, the resistance of WU-04 to the six SARS-CoV-2 variants (Alpha, Beta, Gamma, Delta, Lambda, and Omicron) and two other mainstream coronavirus (SARS-CoV and MERS-CoV) 3CLpro proteins was further investigated. Excitingly, the slight difference in energy values relative to the SARS-CoV-2 system indicates that WU-04 is still highly effective against the coronaviruses, which becomes crucial evidence that WU-04 is a pan-inhibitor of the 3CLpro protein in various SARS-CoV-2 variants and other mainstream coronaviruses. The study will hopefully provide theoretical insights for the future rational design and improvement of novel non-covalent inhibitors targeting the 3CLpro protein. A novel non-covalent inhibitor, WU-04, inhibits several mainstream coronaviruses and is a pan-inhibitor of 3CLpro.