Predictive Insights Into Bioactive Compounds from Streptomyces as Inhibitors of SARS-CoV-2 Mutant Strains by Receptor Binding Domain: Molecular Docking and Dynamics Simulation Approaches

The receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 interacts with the angiotensinconverting enzyme 2 (ACE2) receptor in humans. To date, numerous SARS-CoV-2 variants, particularly those involving mutations in the RBD, have been identified. These variants exhibit differences in transmission, pathogenicity, diagnostics, and vaccine efficacy.

Although therapeutic agents are currently available to inhibit SARS-CoV-2, most provide supportive and symptomatic relief. Moreover, different variants may exhibit resistance to these treatments. This study aimed to identify a potential compound with favorable antiviral effects against SARS-CoV-2 variants.

The study explored drug discovery through structure-based virtual screening of natural products (NPs) from the StreptomeDB database, targeting the ACE2-binding pocket of the SARS-CoV-2 RBD protein. The analysis included the wild-type protein (PDB ID: 6VW1) as well as the Alpha, Beta, Delta, Lambda, Omicron/BA.1, and Omicron/BA.2 variants.

In silico screening identified ‘Stambomycin B’ as a potential compound with the highest binding affinity. Molecular dynamics simulations of the complexes, conducted over 100 ns, confirmed the prediction that ‘Stambomycin B’ could inhibit different SARS-CoV-2 variants effectively.

This study concludes that ‘Stambomycin B’, a macrolide compound produced by Streptomyces ambofaciens, may be a candidate NP for effectively combating all mutants that occur in the binding of SARS-CoV-2 RBD to ACE2, even those that may arise in the future.