Profiling protein interaction networks with functional protein microarrays.

The word protein is derived from the Greek "prota" meaning "of primary importance", a designation which appropriately acknowledges the central role proteins play in biological systems. Following translation and folding into a remarkable array of three-dimensional structures, individual proteins achieve added complexity and functionality through the addition of modifications including glycosylation, acetylation, methylation, and phosphorylation. This complexity is further expanded through the non-covalent interactions that occur between proteins, and it is these interactions that form the foundation for many of the exquisitely regulated cellular processes essential to life. As a result, protein-protein interactions comprise an important class of targets for drug discovery, and modulation of protein-protein binding represents an emerging therapeutic paradigm. Protein microarrays are an important tool to identify and characterize protein interactions, providing the ability to rapidly develop binding profiles between thousands of proteins in a simple multiplex assay. These assays are highly reproducible, sensitive, and scalable and provide an enabling technology for proteomic research within the rubric of systems biology.