Anti-CoV-S2 domain (G5) antibody

General information on Anti-CoV-S2 domain (G5) antibody

The anti-CoV-S2 (G5) antibody is an IgG human immunoglobulin found to bind specifically to the S2 subunit in the C-terminal region of the spike glycoprotein of SARS-CoV-2. Although the S2 subunit does not directly bind the human cell surface receptor ACE2, it still plays a crucial role in the highly infective behavior of the new strain of coronavirus. Studies with other highly infective coronavirus such as SARS-CoV and MERS-CoV, showed this subunit drives the membrane fusion between viral particles and the cellular membrane of epithelial cells.
The S2 protein contains two identical and inverted repeats named heptad repeats (HR1 and HR2). Following the proteolytic cleavage of the spike, this protein becomes exposed and it spontaneously changes conformation into the complex fusion core structure. Understanding the effect anti-CoV-S2 antibodies have on the formation of the core may be crucial to better understand pathologies caused by coronaviruses.
This newly developed anti-CoV-S2 antibody (G5) has been isolated from a highly diverse COVID-19 human antibody library (LiAb-SFCOVID-19™) using recombinantly expressed S2 as the target antigen. The high screening capacity of phage display technologies allowed the discovery of a binder with high affinity towards this biologically relevant domain of SARS-CoV-2. Binding affinity towards S2 was tested and validated using the ELISA platform. Moreover, the stability and ease of production of this fully human IgG antibody were tested by producing it in the transient expression mammalian system, XtenCHO™.