Strategies for identification of peptide growth factors

Numerous peptides are known that have specific functions as growth factors in different tissues. These bioactive peptides are characterized by their ability to bind to high-affinity receptors, by their classification into superfamilies that share homology and function and by their synthesis as large precursor molecules that are processed to active forms. In some cases the precursors themselves also have biological activity. Modulation of growth factor activity at the level of the receptor or effector molecules has great therapeutic potential. This article will outline some of the strategies that have been successful in detecting and identifying growth factors and demonstrating their biological activity.