SARS-CoV-2 spike glycoprotein S1 receptor-binding domain (RBD) (RBD)

The SARS-CoV-2 spike glycoprotein S1 receptor-binding domain (RBD) is a critical functional unit of the viral spike protein that facilitates host cell entry (UniProt P0DTC2). It specifically recognizes and binds to the human Angiotensin-converting enzyme 2 (ACE2) receptor, which is predominantly expressed in the lungs, heart, and kidneys (PubMed: 32142651). This high-affinity binding event is the initial step of infection, leading to the cleavage of the spike protein and subsequent membrane fusion (Nature: 581, 221–224). Because the RBD is the primary interface between the virus and the host, it is the most significant target for neutralizing antibodies produced during natural infection or vaccination (Science: 367, 1260-1263). Therapeutic monoclonal antibodies, such as Sotrovimab and Bebtelovimab, are engineered to bind to the RBD and competitively inhibit its interaction with ACE2 (NIH: COVID-19 Treatment Guidelines). The RBD is also a hotspot for mutations, which can result in the emergence of viral variants that escape neutralization by existing therapeutics and vaccines (NEJM: 384, 1412-1423). Monitoring the structural evolution of the RBD is essential for the development of next-generation vaccines and broad-spectrum antiviral therapies (Nature Medicine: 27, 1139–1141). Overall, the RBD remains a central focus of COVID-19 research due to its role in viral tropism, transmission, and immune evasion.

Other names

SARS-CoV-2 S1-RBDSpike protein receptor-binding domainS-RBDSARS-CoV-2 S1 subunit RBD

Neutralization of viral entry by competitively inhibiting the interaction between the viral receptor-binding domain (RBD) and the host Angiotensin-converting enzyme 2 (ACE2) receptor (PubMed: 32511530).