What is Proteomics?
A bacterial cell may seem simple but it’s actually a complex structure – a gel-like matrix of the cytoplasm, surrounded by both a lipid bilayer cell membrane and a cell wall. The cell must perform many functions including the intake of nutrients, the metabolism of those nutrients, growth, cell division, and the excretion of wastes. What molecules are involved? Although the cytoplasm contains water, proteins, carbohydrates, various ions, and assorted other molecules, proteins do most of the work. A typical bacterium requires more than 4,000 proteins for growth and reproduction. Not all of the proteins are made at the same time and some are made only under special conditions, such as when the cell is stressed or finds itself in a novel environment. The complement of proteins found in this single cell in a particular environment is the proteome. Proteomics is the study of the composition, structure, function, and interactions of the proteins directing the activities of each living cell. I
Helen R. Dickinson, Ph.D. helen.rose@sbcglobal.net Proteomics, an emerging field of biochemistry, is the study of the complete set of proteins in an organism, tissue or cell and the interactions between these proteins. The first step in this process is the separation and identification of the thousands proteins in the sample. Proteomics then focuses on determining the structure, function and interactions of between them. Comparative studies can lead to useful observations on diseases and to targeted new treatments.
The focus of proteomics is a biological group called the proteome. The proteome is dynamic, defined as the set of proteins expressed in a specific cell, given a particular set of conditions. Within a given human proteome, the number of proteins can be as large as 2 million. [1] Proteins themselves are macromolecules: long chains of amino acids. This amino acid chain is constructed when the cellular machinery of the ribosome translates RNA transcripts from DNA in the cell’s nucleus. [2] The transfer of information within cells commonly follows this path, from DNA to RNA to protein.
