Conversion of low-affinity peptides to high-affinity peptide binders by using a β-hairpin scaffold-assisted approach.

Affinity maturation of protein-targeting peptides is generally accomplished by homo- or heterodimerization of known peptides. However, applying a heterodimerization approach is difficult because it is not clear a priori what length or type of linker is required for cooperative binding to a target. Thus, an efficient and simple affinity maturation method for converting low-affinity peptides into high-affinity peptides would clearly be advantageous for advancing peptide-based therapeutics. Here, we describe the development of a novel affinity maturation method based on a robust β-hairpin scaffold and combinatorial phage-display technology. With this strategy, we were able to increase the affinity of existing peptides by more than four orders of magnitude. Taken together, our data demonstrate that this scaffold-assisted approach is highly efficient and effective in generating high-affinity peptides from their low-affinity counterparts.