Identification of potential 3CLpro inhibitors-modulators for human norovirus infections through an advanced virtual screening approach

The present study aimed to screen small molecular compounds such as human noroviruses (HuNoV) inhibitors/modulators that could potentially be responsible for exhibiting some magnitude of inhibitory/modulatory activity against HuNoV 3CLPro. The structural similarity-based screening against the ChEMBL database is performed against known chemical entities that are presently under pre-clinical trial. After the similarity search, remaining molecules were considered for molecular docking using SCORCH and PLANTS. On detailed analyses and comparisons with the control molecule, three hits (CHEMBL393820, CHEMBL2028556, and CHEMBL3747799) were found to have the potential for HuNoV 3CLpro inhibition/modulation. The binding interaction analysis revealed several critical amino acids responsible to hold the molecules tightly at the close proximity site of the catalytic residues of HuNoV 3CLpro. Further, MD simulation study was performed in triplicate to understand the binding stability and potentiality of the proposed molecule toward HuNov 3CLpro. The binding free energy based on MM-GBSA has revealed their strong interaction affinity with 3CLpro.