Severe acute respiratory syndrome coronavirus 2 spike protein (SARS-CoV-2 spike protein) (SARS-CoV-2 S protein)

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is a large, trimeric class I fusion glycoprotein that is essential for viral attachment, fusion, and entry into host cells (UniProt P0DTC2). It consists of two functional subunits: S1, which contains the receptor-binding domain (RBD) for the human angiotensin-converting enzyme 2 (ACE2) receptor, and S2, which mediates the fusion of the viral and host cell membranes (PubMed: 32221306). In the context of host-expressed antigens, mRNA and viral vector vaccines deliver genetic instructions to host cells to synthesize the spike protein, thereby training the immune system to recognize and neutralize the virus (Nature: 10.1038/s41577-020-00480-0). This immunological targeting is the cornerstone of COVID-19 prevention, inducing both humoral (antibody) and cellular (T-cell) immune responses (NIH: COVID-19 Treatment Guidelines). Furthermore, the spike protein is the primary target for therapeutic monoclonal antibodies designed to neutralize the virus in infected or high-risk individuals (PubMed: 33301246). As the virus evolves, mutations in the spike protein, particularly within the RBD, can impact the efficacy of these vaccines and therapeutics, necessitating ongoing monitoring and updated formulations.

Other names

Spike glycoproteinS proteinSurface glycoproteinSARS-CoV-2 SSpike protein

Vaccines (mRNA or viral vector) utilize host cell machinery to express the SARS-CoV-2 spike protein, which acts as an antigen to stimulate B-cell production of neutralizing antibodies and activate T-cell responses (Nature: 10.1038/s41541-021-00369-6). Monoclonal antibodies directly bind to specific epitopes on the spike protein, such as the receptor-binding domain (RBD), to sterically hinder the interaction with the host ACE2 receptor, thereby preventing viral entry (PubMed: 32485146).