Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein receptor-binding domain (RBD) (RBD)

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) glycoprotein is a class I fusion protein that decorates the viral surface and is essential for host cell entry (UniProt P0DTC2) [14]. The receptor-binding domain (RBD), located within the S1 subunit, contains the receptor-binding motif (RBM) which directly interfaces with the human angiotensin-converting enzyme 2 (ACE2) receptor (Nature 2020) [1, 14]. This interaction is the primary determinant of viral tropism and infectivity, as it triggers the conformational changes necessary for membrane fusion (PMC7392467) [11]. Because of its critical role in the viral life cycle, the RBD-ACE2 interface is the primary target for neutralizing antibodies and vaccines (PMC7730510) [16]. Therapeutic agents, such as monoclonal antibodies (e.g., Bamlanivimab, Sotrovimab), work by competitively binding to this interface, thereby blocking the virus from attaching to host cells (PubMed 33208074) [12]. However, the rapid evolution of the virus has led to mutations within the RBD that can enhance binding affinity or facilitate immune escape, posing a significant challenge for long-term therapeutic efficacy (PMC8906914) [18].

Other names

SARS-CoV-2 spike protein receptor-binding domainS1-RBDReceptor-binding motif (RBM)ACE2-interacting surface (ACE2IS)SARS-CoV-2 spike glycoprotein receptor-binding domain at the ACE2 interaction interface

Competitive inhibition of the interaction between the viral receptor-binding domain and the host ACE2 receptor, thereby preventing viral attachment and subsequent cell entry.