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

The SARS-CoV-2 spike protein (Beta variant), associated with the B.1.351 lineage first identified in South Africa, is a trimeric glycoprotein essential for viral attachment and entry into host cells (UniProt P0DTC2). It functions by binding the human Angiotensin-converting enzyme 2 (ACE2) receptor via its receptor-binding domain (RBD) and subsequently facilitating membrane fusion (Nature, 2021). The Beta variant is distinguished by a specific set of mutations, most notably K417N, E484K, and N501Y, which enhance ACE2 binding affinity and promote significant escape from neutralizing antibodies (The Lancet Infectious Diseases, 2021). These mutations render the variant less susceptible to certain monoclonal antibodies, such as bamlanivimab, and reduce the neutralization potency of sera from individuals vaccinated with first-generation mRNA or viral vector vaccines (NEJM, 2021). Consequently, the Beta spike protein serves as a primary target for the development of second-generation vaccines and therapeutic antibodies designed to overcome antigenic drift (NIH, 2021). Understanding the structural changes in the Beta spike protein is essential for monitoring viral evolution and ensuring the continued efficacy of COVID-19 therapeutics and prophylactic measures (WHO, 2021).

Other names

B.1.351 spike protein20H/501Y.V2 spike proteinSouth African variant spike proteinSARS-CoV-2 S protein (B.1.351)

Neutralization of viral entry by blocking the interaction between the receptor-binding domain (RBD) and the host Angiotensin-converting enzyme 2 (ACE2) receptor, or by inhibiting the conformational changes required for membrane fusion.