Anti-S protein (RBD) [aRBD-7]

Absolute Antibody

Anti-S protein (RBD) [aRBD-7]

9

The antibody binds the Spike protein of the SARS-CoV-2.

The VHH with IgG1 Fc formats demonstrated strong binding to both RBD and the entire ectodomain (S1+S2) of SARS-CoV-2 spike in ELISA, with a low nanomolar 50% effective concentration (EC50 respectively 0.522 nM and 0.748 nM). The binding affinity of the VHH format and VHH-Fc formats to RBD were also measured using surface plasmon resonance, with KD values of 3.31 nM and 72 pM respectively. Both VHH and Fc fusion formats could block RBD-ACE2 interaction in a dose-dependent manner, as characterized by competitive ELISA. Furthermore, the fusion of two VHHs with nonoverlapping epitopes resulted in the hetero-bivalent VHHs, aRBD-2-7, which showed significantly higher RBD binding affinities (KD of 0.25 nM). Similarly, their Fc fusions also showed enhanced binding affinities, with a KD value of 0.22 nM. The homo- and hetero-bivalent VHHs exhibited potent neutralizing ability against SARSCoV-2 inoculated onto Vero E6 cells. The 50% neutralization dose was 3.18 ng/ml (0.111 nM), for aRBD-2-7. Finally, the ND50s for aRBD-2-7-Fc was 6.76 ng/ml (0.0606 nM) (Ma et al, 2021; PMID:33658349).

ELISA, Neutralisation/Blocking, Other Application

Research Use Only

Monoclonal

aRBD-7

S

surface glycoprotein

GU280_gp02; spike glycoprotein; surface glycoprotein

Rabbit

IgG

Spike glycoprotein

Virus

-20°C,2°C to 8°C

12352203