SARS-CoV-2 spike protein receptor-binding domain – etesevimab epitope (SARS-CoV-2 RBD etesevimab epitope)

The SARS-CoV-2 spike protein receptor-binding domain (RBD) – etesevimab epitope is a specific molecular site on the surface of the SARS-CoV-2 virus that is targeted by the neutralizing monoclonal antibody etesevimab (also known as LY-CoV016 or JS016) [Medscape, 2021]. This epitope is situated within the receptor-binding motif (RBM) of the RBD, which is the primary region responsible for interacting with the human angiotensin-converting enzyme 2 (ACE2) receptor to facilitate viral entry [NIH, 2021]. Etesevimab binds to this epitope with high specificity and affinity (Kd = 6.45 nM), physically obstructing the RBD-ACE2 interface [PubMed, 2021]. By blocking this interaction, the antibody prevents the virus from attaching to and infecting host cells, thereby neutralizing the pathogen [Wikipedia, 2022]. In clinical practice, etesevimab was frequently administered in combination with bamlanivimab to provide a broader barrier against the development of viral resistance [NIH, 2022]. However, the rapid evolution of SARS-CoV-2 has led to the emergence of variants, such as Omicron, that harbor mutations within this epitope (e.g., K417N, E484K), significantly reducing the neutralizing activity of etesevimab [PubMed, 2021]. Consequently, the use of etesevimab-based therapies has been limited or paused in regions where resistant variants are dominant [FDA, 2022]. Monitoring mutations at this site is essential for assessing the efficacy of existing treatments and for the design of next-generation biologics with broader neutralizing activity [NIH, 2023].

Other names

LY-CoV016 epitopeJS016 epitopeCB6 epitopeSARS-CoV-2 RBD etesevimab binding site

Etesevimab binds to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, specifically within the receptor-binding motif (RBM). This binding physically blocks the interaction between the viral RBD and the human angiotensin-converting enzyme 2 (ACE2) receptor, thereby neutralizing the virus and preventing its entry into host cells [NIH, 2021; PubMed, 2021].