Anti-CoV-RBD (A2) antibody

General information on Anti-CoV-RBD (A2) antibody

The anti-CoV-RBD (A2) antibody is a fully human IgG immunoglobulin designed to target the receptor-binding domain (RBD) of the new pandemic strain of coronavirus, SARS-CoV-2. Targeting this specific domain presents unique advantages when it comes to the development of COVID-19 therapeutic antibodies.

The RBD is responsible for recognizing and binding the specific cell surface marker ACE2 (angiotensin-converting enzyme 2). This interaction further leads to the proteolytic cleavage of the spike exposing the S2 subunit and initiating the formation of the membrane fusion core complex. Antibodies able to block this initial interaction are known as neutralizing antibodies (NAbs). These specific and rare antibodies are on the vanguard of COVID-19 treatments due to their ability to arrest SARS-CoV-2 infections in their earliest stages.

This new antibody was obtained by screening a high-diversity COVID-19 human antibody library (LiAb-SFCOVID-19™) using phage display technology (i.e. biopanning) and recombinantly expressed RBD as the desired target. It capitalizes on the immune repertoire developed in patients who have been infected with COVID-19. Additionally, the specificity and affinity of the newly developed molecule were tested in the ELISA platform. Its stability and ease of production were further confirmed by consistently obtaining high production yields in XtenCHO™, a transient mammalian system based on an engineered variant of CHO.

Moreover, the neutralizing activity of antibody R3P2-A2 was confirmed in vitro through the indirect detection assay: SARS-CoV-2 Surrogate Virus Neutralization kit. The assay works on the principle of direct competition between candidate antibodies and the ACE2 for the binding pocket of RBD. This antibody and other similar products serve as effective research tools to either detect the presence of SARS-CoV-2 in multiple samples in ELISA tests, as well as to potentially better understand the mechanism of infection in the new coronavirus.