Identification of small peptides that interact specifically with a small organic dye

Using a “one‐bead one‐peptide” combinatorial peptide library method, we have been able to identify peptide ligands that interact specifically with various macromolecular targets such as monoclonal antibodies, streptavidin, avidin, MHC‐Class I molecules, proteases, growth factor receptors, and gpIIb/IIIa integrin. In this paper, we test the hypothesis that small peptides that interact specifically with a small organic molecule can also be identified using this combinatorial peptide method. Using a small organic dye molecule, indigo carmine, as a color probe to screen a random L‐heptapeptide and two D‐hexa and octapeptide libraries, we were able to identify a specific peptide binding motif. Potential applications of this technology are described. © 1994 Wiley‐Less, Inc.