Sarbecovirus spike protein receptor-binding domain (RBD) (RBD)

The Sarbecovirus spike protein receptor-binding domain (RBD) is a critical functional unit located within the S1 subunit of the viral spike (S) glycoprotein, found in viruses such as SARS-CoV and SARS-CoV-2 [UniProt, 2024]. Its primary biological function is to mediate the initial attachment of the virus to host cells by specifically binding to the human Angiotensin-converting enzyme 2 (ACE2) receptor [Cell Mol Immunol, 2020]. This high-affinity interaction triggers conformational changes in the spike protein that facilitate membrane fusion and subsequent viral entry into the host cell [Nature, 2021]. As the most accessible and essential interface for infection, the RBD is the primary target for neutralizing antibodies elicited by both natural infection and vaccination [Science Immunology, 2020]. Therapeutic monoclonal antibodies, such as Sotrovimab and Bebtelovimab, are designed to bind the RBD and sterically or competitively block its interaction with ACE2, thereby neutralizing the virus [PMC, 2023]. However, the RBD is a highly mutable region, and the emergence of variants with mutations in the receptor-binding motif (RBM) poses a significant challenge by enabling viral escape from existing immune responses and therapeutic agents [PubMed, 2023]. Consequently, the RBD remains a central focus for the development of broad-spectrum vaccines and pan-sarbecovirus therapies [ACS Cent Sci, 2023].

Other names

S-RBDSpike protein receptor-binding domainSARS-CoV-2 RBDSARS-CoV RBDSarbecovirus RBDReceptor-binding domain of the spike glycoprotein

Neutralization of viral entry by competitively or sterically blocking the interaction between the viral receptor-binding domain and the host cell receptor, such as Angiotensin-converting enzyme 2 (ACE2).