The broad utility of soluble peptide libraries for drug discovery

The use of soluble peptide combinatorial libraries made up of millions, billions, or now even trillions (10(6), 10(9) and 10(12)) of peptides, currently used in a wide range of investigations, is discussed. These include: antibody/peptide antigen studies, the development of new ligands through the use of radio receptor assays, novel enzyme inhibitors, antibacterial and antifungal peptides through the use of microdilution assays, antivirals in plaque assays, and cardiovascular drugs in in vivo studies. The use of a new positional scanning library composed of approximately four trillion decapeptides is illustrated in a radio receptor assay. The criteria by which libraries, in general, can be judged will be described.