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

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) beta variant spike glycoprotein is a trimeric class I fusion protein located on the surface of the B.1.351 variant of the virus [8, 15]. It plays a fundamental role in viral pathogenesis by mediating attachment to the host cell receptor, angiotensin-converting enzyme 2 (ACE2), and facilitating the fusion of the viral envelope with the host cell membrane [6, 13]. The Beta variant is characterized by specific mutations in the receptor-binding domain (RBD), including K417N, E484K, and N501Y, which enhance binding affinity to ACE2 and contribute to significant immune evasion [8, 9]. These structural alterations allow the virus to partially bypass neutralizing antibodies elicited by previous infections or early-generation vaccines [9, 10]. Consequently, this protein is a primary target for the development of updated vaccines and monoclonal antibody therapies designed to restore or enhance neutralization potency [16, 19]. Understanding the structural dynamics of this variant's spike protein is crucial for monitoring viral evolution and informing public health strategies [5, 20]. The protein's high degree of glycosylation also plays a role in shielding it from the host's immune system [3, 18]. Therapeutic agents such as sotrovimab and the tixagevimab/cilgavimab combination were developed to target conserved regions of the spike to maintain efficacy against such variants [17, 18]. Monitoring the emergence of these mutations is vital for the ongoing adaptation of medical countermeasures [5, 9]. Overall, the Beta variant spike protein represents a key molecular target in the global effort to control COVID-19 [16, 19].

Other names

B.1.351 spike protein501Y.V2 spike proteinSouth African variant spike proteinSARS-CoV-2 S protein (Beta variant)Spike glycoprotein (B.1.351)

Neutralization of viral infection by binding to the receptor-binding domain (RBD) or N-terminal domain (NTD) of the spike protein, thereby blocking its interaction with the host ACE2 receptor and preventing viral entry and membrane fusion [5, 13, 16].