A neutralizing human antibody binds to the N-terminal domain of the Spike protein of SARS-CoV-2.

TLDR: The epitope of 4A8 is defined as the N-terminal domain (NTD) of the S protein by determining with cryo–eletron microscopy its structure in complex with the Sprotein, which points to the NTD as a promising target for therapeutic mAbs against COVID-19.

Abstract: Developing therapeutics against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be guided by the distribution of epitopes, not only on the receptor binding domain (RBD) of the Spike (S) protein but also across the full Spike (S) protein We isolated and characterized monoclonal antibodies (mAbs) from 10 convalescent COVID-19 patients Three mAbs showed neutralizing activities against authentic SARS-CoV-2 One mAb, named 4A8, exhibits high neutralization potency against both authentic and pseudotyped SARS-CoV-2 but does not bind the RBD We defined the epitope of 4A8 as the N-terminal domain (NTD) of the S protein by determining with cryo-eletron microscopy its structure in complex with the S protein to an overall resolution of 31 angstroms and local resolution of 33 angstroms for the 4A8-NTD interface This points to the NTD as a promising target for therapeutic mAbs against COVID-19