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

The SARS-CoV-2 Omicron BA.2 spike protein is a large, homotrimeric class I fusion glycoprotein located on the surface of the virus. It is the primary mediator of viral entry into host cells by binding to the human angiotensin-converting enzyme 2 (ACE2) receptor via its receptor-binding domain (RBD) [1, 4]. The BA.2 subvariant spike is characterized by a specific set of mutations that distinguish it from the original BA.1 Omicron variant, contributing to increased transmissibility and significant evasion of neutralizing antibodies [2, 4]. As the principal antigen for most COVID-19 vaccines and the target for therapeutic monoclonal antibodies, it plays a critical role in both the infection process and the host immune response [3, 5]. Drugs targeting this protein typically aim to neutralize the virus by blocking its attachment to host cells or preventing the structural rearrangements necessary for membrane fusion [3]. However, the high mutation rate of the spike protein presents a major challenge for long-term therapeutic efficacy and vaccine durability [5]. The BA.2 lineage specifically lacks the 69-70 deletion found in BA.1, which affects diagnostic screening methods like S-gene target failure [2].

Other names

Spike glycoproteinS proteinBA.2 spikeB.1.1.529.2 spike proteinSARS-CoV-2 S protein

Neutralization of viral entry by blocking the receptor-binding domain (RBD) interaction with host ACE2 receptors or inhibiting S2-mediated membrane fusion.