Impact of the SARS-CoV-2 S-protein G476S mutation on the interaction with human ACE-2 receptor and neutralizing antibodies
Abstract The G476S mutation of the SARS-CoV-2 S-protein occurs in the receptor binding domain (RBD), the region that binds to the human angiotensin-converting enzyme 2 (hACE-2) receptor and also the main target for neutralizing antibodies. The 476S variant was first reported in the USA. Emerging evidence show that the 476S variant resists neutralization by antibodies such as S2E12 and CC6.29. The impact of the mutation on the interactions with hACE-2 receptor and the dynamics of the S-protein, has not been not fully explored. Here, we provide insights into the structure dynamics of the 476S variant and investigate the impact of the mutation on interactions with hACE-2 and selected neutralizing antibodies. We report that the mutation induces a destabilization effect in the RBD and an increased flexibility for most of the receptor binding residues. The mutation, however, does not affect the interactions with the hACE-2 receptor. Both Gly-476 and Ser-476, although located within the hACE-2 interacting residue hotspot, do not contribute to the stabilization of the RBD-hACE-2 complex. Our findings suggest that both H014 and P2P-2F6 antibodies neutralize the 476G and 476S S-proteins with similar efficacy.