Coronavirus spike glycoprotein receptor-binding domain (RBD (Receptor-binding domain))

The coronavirus spike glycoprotein receptor-binding domain (RBD) is a critical structural motif within the S1 subunit of the coronavirus spike (S) protein, including that of SARS-CoV-2, responsible for direct interaction with specific host cell receptors, most notably human angiotensin-converting enzyme 2 (ACE2)[1][4][6]. The RBD mediates the initial attachment of the virus to the host cell, enabling subsequent membrane fusion and viral entry. Due to its crucial role in infection, the RBD is the major target for neutralizing antibodies and forms the basis of most COVID-19 vaccines and therapeutic antibody strategies[3][4][6]. The RBD shows high sequence and structural conservation within some betacoronaviruses but accumulates mutations that can modulate receptor specificity and immune evasion[1][4]. In addition to ACE2, RBDs in different coronaviruses recognize diverse receptors, contributing to virus host range and zoonotic capacity[1][2]. The RBD is highly immunogenic and is frequently monitored as a biomarker of vaccine efficacy[3][7]. Key therapeutic challenges include viral escape from RBD-targeting antibodies and ongoing structural variation in circulating viral strains[3].

Other names

Spike protein RBDS1 receptor-binding domainSARS-CoV-2 spike RBDS protein RBD

Inhibition of RBD–ACE2 interaction to block viral entry Neutralization by antibody binding to RBD, preventing host cell attachment Induction of adaptive immune response (via vaccines exposing RBD epitopes)