Fig. 1
From: Engineering PD-1-targeted small protein variants for in vitro diagnostics and in vivo PET imaging

Concept of Myomedin β-sheet combinatorial library and selected MBA variants’ binding curves measured by ELISA. A Side view and B top view to the human myomesin-1 domain 10 in cartoon representation, showing positions of residues selected for randomization. Highlighted are the Cα positions of residues N1276, I1278, E1281, T1315, T1317, Q1319, Q1321, K1324, T1326, H1328, T1330, and V1332 numbered according to the UniProt (UniProt, 2019) P52179 record. The residue color scale represents the mutability score, from blue to red for low to high mutability. C Surface representation of the Myomedin scaffold with the β-sheet patch in magenta and the previously defined Myomedin loop library in red [34]. D Scheme of Myomedin β-sheet library assembly using multistep PCR. E Binding of selected MBA variants to recombinant hPD-1 receptor assessed by ELISA assay. Detection of the signal was performed using anti-V5 tag-HRP conjugated antibody at 450 nm