Constrained peptides as binding entities.

Displaying proteins and peptides on genetic packages and selecting packages that display high-affinity binders allows large numbers of peptidyl compounds to be tested for binding to targets. Phage-displayed libraries of unstructured peptides (UPs) have yielded binders for some targets, but not for many others. Therefore, more attention is being paid to peptidyl compounds that have varied regions that are subject to conformational constraint.