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

The SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) is a critical component of the S1 subunit of the viral spike protein that is essential for initiating infection [4, 6]. Its primary biological function is to mediate high-affinity binding to the human host cell receptor, angiotensin-converting enzyme 2 (ACE2), specifically through a subregion known as the receptor-binding motif (RBM) [5, 19, 20]. This interaction at the ACE2 interface triggers conformational changes in the spike protein that facilitate viral-host membrane fusion and subsequent entry of the viral genome into the cell [7, 14]. As the primary interface for viral attachment, the RBD is the most significant target for neutralizing antibodies, whether induced by natural infection, vaccination, or administered as monoclonal antibody therapies [2, 17]. Therapeutic agents, such as monoclonal antibodies (e.g., Sotrovimab, Casirivimab), work by binding to the RBD and sterically blocking its interaction with ACE2, thereby neutralizing the virus [1, 3, 19]. However, the RBD is highly prone to mutations, which can lead to the emergence of variants of concern that exhibit increased transmissibility or the ability to evade existing immune responses and therapeutic treatments [11, 16].

Other names

Spike RBDS1-RBDReceptor-binding domain of the spike proteinACE2-interacting surface (ACE2IS)Receptor-binding motif (RBM)

Neutralization of viral particles by blocking the interaction between the viral receptor-binding domain and the host angiotensin-converting enzyme 2 receptor, thereby preventing viral entry into host cells [1, 3, 10].