Proteomics, << proh tee OM ihks, >> is the study of proteins as they exist within the bodies of living things. Proteins are large, complex molecules of carbon, hydrogen, nitrogen, and oxygen. Living bodies use proteins to build cells, which consist mainly of proteins, and to carry out the cells’ work. The term proteome describes the collection of proteins coded within a genome. A genome refers to all genes (units of heredity) that occur on the chromosomes (threadlike structures) of a cell. One of the key goals of proteomics involves determining the sequence, or order, of all proteins in the genomes of different species. Proteomics also attempts to learn more about how proteins function.
When scientists determine the sequence of genes in an organism’s genome, they can then predict that genome’s protein sequence. However, not all the proteins in the predicted sequence may exist within the organism. Many genomes have the potential to create proteins that the organism does not actually produce. To determine more precisely what proteins are produced, many scientists use a method called two-dimensional gel electrophoresis. This method separates proteins according to their mass and electric charge.
Other techniques help determine how proteins function. For example, a protein’s shape provides clues about its role in the body. Scientists can decipher the shapes of individual proteins using X-ray crystallography. In this procedure, researchers create a protein crystal from numerous copies of an individual protein molecule. They then scatter X rays through atoms in the crystal. Researchers also learn about protein function by isolating individual proteins and testing how they interact with other molecules.
Microchips containing proteins may someday provide a valuable tool in medicine. Doctors could use such chips to diagnose and treat various diseases.
