Comparison of Clinically Approved Molecules on SARS-CoV-2 Drug Target Proteins: A Molecular Docking Study

There are numerous drug design studies conducted all over the globe. Most of these studies target the receptor-binding domain of spike protein of SASR-CoV-2, which is known to bind human ACE2 receptor and SARS-CoV-2 main protease, vital for the virus’ replication. However, there might be a third target, human furin protease, which cleaves the virus’ S1-S2 domains taking active role in its entry into the host cell. In this study we docked five clinically used drug molecules, favipiravir, hydroxychloroquine, remdesivir, lopinavir, and ritonavir onto three target proteins, receptor binding domain of SARS-CoV-2 spike protein, SARS-CoV-2 main protease, and human furin protease. Computational results clearly showed that all ligands provided higher binding affinities towards furin protease, except hydroxychloroquine and ritonavir yielding the highest binding affinity. This proves that furin protease might be targeted for drug design studies and must be further explored in vitro and in vivo.