Biologically displayed random peptides as reagents in mapping protein-protein interactions.

Random peptide libraries, also known as combinatorial peptide libraries, represent an exciting new set of reagents for the purposes of mapping protein-protein interactions and drug discovery. Millions to trillions of peptides can be expressed biologically, such that the plurality of peptides are accessible and physically linked to the genetic element encoding them. These libraries can be screened by affinity selection to isolate those members in the library that display binding to the target molecule of interest. Sequencing of the associated DNA or RNA elements then leads to the elucidation of the binding peptide's primary structure. From the collection of isolated binding peptides, a consensus motif is frequently evident; these motifs are informative in investigating the interactions of natural proteins. Finally, because synthetic forms of identified peptides are often pharmacological antagonists, they can serve as drug leads. [ABSTRACT FROM AUTHOR]