Figure 1
Backgrounds of the designed mutagenesis targeting the VH-FR1 performed in this study. (a) Selected data of our previous CAP-based antibody-breeding experiments with scFvs against cortisol7. A schematic illustration of the primary structures and Ka values of wt-scFv and improved scFvs having only a single amino acid substitution or insertion in the VH-FR1. In wt-scFv, the VH and VL domains were combined via a linker sequence VSS(GGGGS)3T. (b) The most common amino acids found at the positions 1–30 in VH (i.e., the VH-FR1) in different subgroups as defined by Kabat et al.18. The frequency of appearance of each residue is shown with different colors27: magenta, invariant (> 95%) and common in all subgroups; green, “subgroup-specific residues” that are invariant within the relevant subgroup(s). The VH-FR1 amino acid sequence of wt-scFv is also shown for comparison. (c) The frequency of amino acids at the positions 1–10, 21, 23, 28, and 29 in VH, compiled for 1,820 antibodies that were available in the Kabat database18,26. The detailed data listing for the positions 1–30 is available in Supplementary Table S1.
