Computational Ab Initio Interaction Analyses between Neutralizing Antibody and SARS-CoV-2 Variant Spike Proteins Using the Fragment Molecular Orbital Method

The interaction energies between the receptor-binding domain of SARS-CoV-2 spike proteins and neutralizing antibody CC12.1 Fab were calculated using the fragment molecular orbital method. South African and Brazilian variants showed weaker interactions than the wild-type. Mutations, K417N/T and E484K, were considered to be responsible for escape from the antibody.