SARS-CoV-2 Alpha variant spike glycoprotein (Spike (S) glycoprotein)

The SARS-CoV-2 Alpha variant spike glycoprotein is a large, trimeric, type I transmembrane protein displayed on the surface of the viral particle. It is responsible for attachment to the host cell receptor, ACE2, via its S1 subunit, and then mediates fusion of viral and cellular membranes via its S2 subunit, enabling viral entry. The Alpha variant (B.1.1.7) spike protein is distinguished by a specific mutation profile, notably N501Y and others, that enhance ACE2 binding and contribute to increased transmissibility and immune evasion. The spike protein is highly glycosylated, forming trimeric spikes visible on electron microscopy that give coronaviruses their characteristic appearance. It is the principal antigenic target for diagnostics, monoclonal antibodies, and all licensed COVID-19 vaccines. It remains the most important determinant of host range, cell tropism, and immune response among SARS-CoV-2 variants.

Other names

Spike glycoproteinS glycoproteinS proteinCoronavirus spike proteinSARS-CoV-2 spike proteinAlpha variant spike (B.1.1.7 spike)

Drugs targeting SARS-CoV-2 Alpha variant spike glycoprotein typically block receptor binding on ACE2 to neutralize the virus, inhibit fusion activation or proteolytic cleavage (e.g., TMPRSS2 inhibitors), prevent conformational changes required for membrane fusion, or activate immune responses to eliminate infected cells (vaccine antigens).