SARS-CoV-2 spike glycoprotein receptor-binding domain (SARS-CoV-2 S RBD) (SARS-CoV-2 S RBD)

The SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) is a critical region of the S1 subunit of the viral spike protein, serving as the primary interface for binding to the human angiotensin-converting enzyme 2 (ACE2) receptor to initiate viral entry (NIH, 2023). The bebtelovimab epitope refers to a specific, relatively conserved site within the RBD targeted by the monoclonal antibody bebtelovimab (LY-CoV1404). This epitope was initially selected for its high degree of conservation across early SARS-CoV-2 variants, including Alpha, Beta, Gamma, Delta, and early Omicron lineages (Westendorf et al., 2022). By binding to this site, bebtelovimab neutralizes the virus by sterically hindering the RBD-ACE2 interaction. However, the rapid antigenic drift of SARS-CoV-2 has led to mutations in this epitope, particularly in Omicron subvariants like BQ.1 and XBB.1.5, which render the antibody ineffective (FDA, 2022). Consequently, while the RBD remains a vital therapeutic target, the specific bebtelovimab epitope illustrates the ongoing challenge of viral evolution in the development of durable monoclonal antibody therapies.

Other names

Spike protein RBDS-RBDSARS-CoV-2 S1 subunit RBDBebtelovimab epitopeLY-CoV1404 binding site

Bebtelovimab binds to a specific, highly conserved epitope on the SARS-CoV-2 spike protein receptor-binding domain (RBD), which sterically blocks the interaction between the RBD and the human angiotensin-converting enzyme 2 (ACE2) receptor, thereby preventing viral entry into host cells (Westendorf et al., Cell Reports, 2022; NIH COVID-19 Treatment Guidelines, 2023).