Nature Potential for COVID-19: Targeting SARS-CoV-2 Mpro Inhibitor with Bioactive Compound
Kaushik Kumar Bharadwaj, Tanmay Sarkar, Arabinda Ghosh, Debabrat Baishya, Bijuli Rabha, Manasa Kumar Panda, Bryan Raveen Nelson, Akbar John, Hassan Ibrahim Sheikh, Bisnu Prasad Dash, Hisham Atan Edinur, Siddhartha Pati · ChemRxiv · 2021
Corona viruses were first identified in 1931 and SARS-CoV-2 is the most recent. COVID-19 is a pandemic that put most of the world on lockdown and the search for therapeutic drugs is still on-going. Therefore, this study uses in silico screening to identify natural bioactive compounds from fruits, herbaceous plants and marine invertebrates that are able to inhibit protease activity in SARS-CoV-2(PDB: 6LU7). We have used various screening strategies such as drug likeliness, antiviral activity value prediction, molecular docking, ADME (absorption, distribution, metabolism, and excretion), molecular dynamics (MD) simulation and MM/GBSA (molecular mechanics/generalized born and surface area continuum solvation). 17 compounds were shortlisted using Lipinski’s rule. 5 compounds revealed significantly good predicted antiviral activity values and out of them only 2 compounds, Macrolactin A and Stachyflin, showed good binding energy values of -9.22 and -8.00 kcal/mol within the binding pocket, catalytic residues (HIS 41 and CYS 145) of Mpro. These two compounds were further analyzed for their ADME properties. The ADME evaluation of these 2 compounds suggested that they could be effective as therapeutic agents for developing drugs for clinical trials. MD simulations showed that protein-ligand complexes of Macrolactin A and Stachyflin were stable for 100 nano seconds. The MM/GBSA calculations of Mpro – Macrolactin A complex indicated higher binding free energy (-42.58 ± 6.35 kcal/mol) with Mpro protein target receptor (6LU7). DCCM and PCA analysis on the residual movement in the MD trajectories confirmed the good stability on Macrolactin A bound state of 6LU7. This signify the stable conformation of 6LU7 with high binding energy with Macrolactin A. Thus, this study showed that Macrolactin A could be an effective therapeutical agent for SARS-CoV-2protease (6LU7) inhibition. Additional in vitro and in vivo validations are needed to determine efficacy and dose of Macrolactin A in biological systems.