Spike glycoprotein receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (Spike RBD (SARS-CoV-2))

The **spike glycoprotein receptor-binding domain (RBD)** of severe acute respiratory syndrome coronavirus 2 (*SARS-CoV-2*) is a discrete domain (amino acids 319–541) within the S1 subunit of the viral trimeric spike (S) protein[1][3][6]. The RBD is responsible for high-affinity and specific binding to the host cell surface receptor, **angiotensin-converting enzyme 2 (ACE2)**, thereby mediating viral attachment and entry into target cells[2][3][5][6][7]. Structurally, the RBD comprises a core of antiparallel β-sheets and a receptor-binding motif (RBM); it undergoes conformational changes that regulate accessibility for ACE2 binding and immune recognition[4][5][7]. The RBD is the primary target for neutralizing antibodies in natural infection and vaccination and is under strong selective pressure in the emergence of viral variants[8]. It is an established and critical target for vaccines and therapeutic antibodies against COVID-19 and plays a central role in viral pathogenesis and interspecies transmission[5][7][8].

Other names

Receptor-binding domain of spike protein (RBD)SARS-CoV-2 spike RBDS1 receptor-binding domainRBD of S protein

Direct neutralization by blocking ACE2 binding; Promotion of anti-viral immune response; Inhibition of viral entry/fusion