New Developments in Proteomics

Abstract

NC Med J March/April 2007, Volume 68, Number 2 enes are relatively static instruction sets for protein manufacturing processes in the cell. Fundamental genetic components (encoding regions) are linked, modified, and combined to create a wide variety of unique protein products. The total number of human protein-encoding genes has been estimated by the Human Genome Sequencing Consortium to be 20 000 to 25 000 genes. The size of the proteome, the complete set of proteins expressed from the genome, is far larger and may exceed 100 000 proteins in humans. Proteomics, the study of the proteome, is the next great challenge in biology and medicine and may rival genomics in complexity, costs, and benefits. Legacy protein chemistry techniques such as chromatography, electrophoresis, and affinity columns have been used for decades and are an effective means to identify and characterize individual proteins. Proteomics is distinguished from protein chemistry in that proteomics tends to focus on patterns and systems of protein expression rather than on single components. Proteomic techniques are capable of simultaneously examining the expression of thousands of proteins to identify unique patterns associated with phenotypes, tissues, disease states, and responses to environmental or therapeutic exposures. Clinical proteomics encompasses an understanding of protein systems in pathologic processes leading to new diagnostic and prognostic tests, the discovery of protein targets for new pharmacologic therapies, and the identification of patients most likely to benefit from these therapies. The central problem in clinical proteomics is to distinguish and identify multiple proteins related to a disease or condition, even when these proteins are initially unknown. The underlying assumption is that a given disease or condition is manifested by a pattern of protein expression that is unique and identifiable. Proteomic methods compare protein expression in patients with and without a given condition to identify unique patterns or profiles of protein expression related specifically to that condition. Once a condition-specific protein expression pattern is discovered, its constituent proteins are identified New Developments in Proteomics