Figure 2.

ELISA-like assays to evaluate the binding of the designed peptides to their targets. (A) and (B) show a schematic of the binding assays used. (A) Target proteins are immobilized to the ELISA wells, whereas in (B) the peptides are attached to the wells by binding to immobilized anti-FLAG antibodies. The affinity of the designed peptides to the immobilized S protein, RBD, and PBS (used as a control) is shown in (C). Values are normalized to that obtained by a commercial anti-S antibody (OD₄₅₀). The tendency of the immobilized designed peptides to capture the S protein from a mixture of cell lysates plus the S protein is represented in (D). Values are normalized to that obtained by the R1 peptide for the detection of S protein in a mixture of cell lysates and the S protein. Each experiment is repeated at least four times independently.