Impact of Mutations in the SARS-CoV-2 Spike RBD Region of BA.1 and BA.2 Variants on its Interaction with ACE2 Receptor Protein

Abstract

The COVID-19 pandemic started at the onset of 2020 and still thriving due to its continuous mutation and evolution into new strains. Omicron strain has been recently categorized as a variant of concern(VoC) by WHO and based on mutations, it is divided into BA.1 and BA.2. In this study, we compared the interaction profile of RBD of the spike protein of the BA.1 and BA.2 variant of SARS-CoV-2 with ACE2 receptor. From the molecular dynamics simulation study, we observed the spike protein of BA.1, and BA.2 variant utilizes unique strategies to have a stable binding with ACE2. The binding affinity of the spike protein of the BA.2 variant-ACE2 complex is indeed high (GBTOT=-23.87 kcal/mol) in comparison with the spike protein of BA.1 variant-ACE2 complex (GBTOT=5.38 kcal/mol). Stable binding of spike protein to ACE2 is essential for virus entry, and the interactions between them should be understood well for the treatment modalities.