Receptor-binding domain of the SARS-CoV-2 spike glycoprotein (RBD of SARS-CoV-2 spike (S) protein)

The receptor-binding domain (RBD) of the SARS-CoV-2 spike glycoprotein is a critical functional subunit located within the S1 region of the trimeric spike protein, responsible for direct interaction with the host cellular receptor angiotensin-converting enzyme 2 (ACE2)[5][9]. The RBD mediates the initial attachment of the virus to host cells, triggering subsequent steps required for membrane fusion and viral entry[3][7][9]. Structurally, the RBD comprises approximately residues 319–541 of the spike protein and exhibits dynamic "up" (receptor-accessible) and "down" (receptor-inaccessible) conformations within the spike trimer[6][5]. The RBD is the primary target for neutralizing antibodies, making it a central focus for both therapeutic monoclonal antibody development and vaccine design[1][4][7][8]. Mutations in the RBD are closely tracked as they can impact viral infectivity, transmissibility, and immune escape[9]. Because of its essential role in viral entry and as the dominant antigenic site, the SARS-CoV-2 spike RBD is among the most validated and intensively studied therapeutic targets in COVID-19 research.

Other names

Spike RBDSARS-CoV-2 spike protein RBDS1 receptor-binding domainCOVID-19 spike RBD

Blockage of RBD-ACE2 interaction (prevents viral attachment and entry) Neutralization of virus by direct binding (antibody-mediated) Competitive inhibition with soluble ACE2/receptor mimics