SARS-CoV-2 spike glycoprotein S1 subunit receptor-binding domain and N-terminal domain (Spike protein S1 RBD and NTD)

The SARS-CoV-2 spike glycoprotein is a class I viral fusion protein found on the surface of the coronavirus and is essential for mediating viral entry into host cells. The S1 subunit contains two critical domains: the N-terminal domain (NTD) and the receptor-binding domain (RBD). The RBD is responsible for binding to the host cell receptor angiotensin-converting enzyme 2 (ACE2), which is the primary step for host cell entry. The NTD, although less well characterized than the RBD, can bind sugar molecules and may play roles in immune evasion and, in some variants, potentially influence tropism or infection efficiency. The spike protein is the major antigen for neutralizing antibodies and the primary target for both therapeutic antibodies and COVID-19 vaccines. Due to its surface exposure and role in infection, mutations in the RBD and NTD are key drivers of immune escape and variant emergence. The protein is heavily glycosylated, providing a glycan shield that helps the virus evade the host immune response[1][2][3][4][6][7].

Other names

Spike glycoprotein S1 receptor-binding domain (RBD)Spike glycoprotein S1 N-terminal domain (NTD)SARS-CoV-2 S1 RBDSARS-CoV-2 S1 NTDSpike protein S1

Antibodies targeting the RBD block ACE2 interaction, preventing viral entry Vaccines induce immune response by presenting spike protein antigens Small molecule and peptide inhibitors may interfere with spike-mediated membrane fusion