Spike S1 (RBD)

Spike S1 (RBD) refers to the receptor-binding domain (RBD) located within the S1 subunit of the coronavirus Spike (S) protein. This domain is responsible for specifically recognizing and binding to the host cell receptor, such as ACE2 in SARS-CoV-2, facilitating viral entry. Because of its critical role in infection, the S1 RBD is a major target for vaccines, neutralizing antibodies, and diagnostic assays.