Fig. 3.

Interaction of the ACE2-Fc constructs with the SARS-CoV-2 RBD. a Surface plasmon resonance (SPR) was performed to obtain binding curves of ACE2-Fc fusion constructs and an unrelated Fc fusion protein (aflibercept) to an immobilized RBD from SARS-CoV-2. An exemplary binding curve is shown (RU = Response Units). b Binding constants of the ACE2-Fc constructs towards the RBD of SARS-CoV-2 (Mean ± SD of triplicate measurements). c ACE2-Fc fusion proteins were pre-incubated with the SARS-CoV-2 spike S1 protein and tested in a competition ELISA for their ability to neutralize S1 binding to immobilized ACE2 protein. Potent inhibition of SARS-CoV-2 spike S1 protein by ACE2-IgG4-Fc constructs (left) and ACE2-IgG1-Fc constructs (right). Data are represented as means ± SD of at least two independent experiments.