Human CellExp™ SARS-CoV-2 S1 (E484K), Recombinant

SARS-CoV-2, the causative virus of COVID-19, uses the viral Spike (S) protein for host cell attachment and entry. The virus uses multiple host targets including the human protease Furin, Angiotensin converting enzyme 2 (ACE2), Neuropilin-1 (NRP1) and the transmembrane protease serine 2 (TMPRSS2) for host cell entry. The S protein has two domains S1 and S2, where S1 facilitates initial binding to the receptor and the S2 domain drives the membrane fusion and eventual entry of the virus. The S glycoprotein serves as an important target for monoclonal antibodies, entry inhibitors, and vaccines. Within the S1 protein, the conserved receptor-binding domain (RBD) binds with a high affinity for ACE2. Recently, increasing concern has been garnered over the discovery of new SARS-CoV-2 variants with the ability to escape antibody-mediated protection either by previous infection or vaccination. The E484K mutation, which occurs in the RBD, is a substitution from a glutamic acid (E) to lysine (K) at position 484. It is one of the few mutations found in both the B.1.351 (South African) and P.1 (Brazil) strains. According to the CDC, they claim a moderate impact on neutralization by monoclonal antibody therapeutics and convalescent/post-vaccination sera for the E484K mutation. Furthermore, the South African strain is estimated to be roughly 50% more transmissible compared to other dominant lineages based on the rate of its spread.