Severe acute respiratory syndrome coronavirus 2 Beta variant spike protein (SARS-CoV-2 B.1.351 S protein) (SARS-CoV-2 B.1.351 S protein)

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Beta variant spike protein is the primary surface glycoprotein of the B.1.351 lineage, first identified in South Africa. This protein is essential for viral pathogenesis, as it facilitates host cell entry by binding to the human angiotensin-converting enzyme 2 (ACE2) receptor [1, 2]. The Beta variant spike is characterized by key mutations in its receptor-binding domain (RBD), specifically K417N, E484K, and N501Y, which collectively enhance ACE2 binding affinity and promote significant escape from neutralizing antibodies [3, 4]. These structural alterations reduce the effectiveness of several first-generation monoclonal antibodies and certain vaccine-induced immune responses [5, 6]. As a therapeutic target, the spike protein is the focus of neutralizing monoclonal antibodies like Sotrovimab and updated vaccine boosters designed to provide broader protection against evolving variants [7, 8]. Monitoring the mutations within this protein is critical for assessing the ongoing risk of immune evasion and guiding the development of next-generation COVID-19 therapeutics [9]. [1] WHO. (2021). Tracking SARS-CoV-2 variants. [2] Zhou, D., et al. (2021). Nature. Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and vaccine-induced sera. [3] Tegally, H., et al. (2021). Nature. Detection of a SARS-CoV-2 variant of concern in South Africa. [4] Cele, S., et al. (2021). Nature. Escape of SARS-CoV-2 501Y.V2 from neutralization by convalescent plasma. [5] Wang, P., et al. (2021). Nature. Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7. [6] Collier, D. A., et al. (2021). Nature. Sensitivity of SARS-CoV-2 B.1.1.7 to mRNA vaccine-elicited antibodies. [7] Cathcart, A. L., et al. (2022). Nature. The dual function of the SARS-CoV-2 spike protein. [8] FDA. (2021). Fact Sheet for Healthcare Providers: Emergency Use Authorization of Sotrovimab. [9] NIH. (2023). COVID-19 Treatment Guidelines: Anti-SARS-CoV-2 Monoclonal Antibodies.

Other names

Beta variant spike proteinB.1.351 spike protein501Y.V2 spike proteinSARS-CoV-2 South African variant spike protein

Neutralization of viral entry by blocking the interaction between the receptor-binding domain (RBD) and the host ACE2 receptor; inhibition of S2-mediated membrane fusion; induction of antibody-dependent cellular cytotoxicity (ADCC).