Proteomics--application to the brain.

Publisher Summary Proteomics is an experimental approach to explain the information contained in the genomic sequences in terms of the structure, function, and control of biological processes and pathways. The proteome is the quantitative expression profile of a cell, an organism, or a tissue under exactly defined conditions. The systematic separation, identification, and characterization of proteins of the nervous system offer a basis for research trying to elucidate the mechanisms of neurodegenerative diseases. The studies of neurodegenerative diseases, on the basis of molecular phenotypes, lead to a new understanding of neurodegeneration. Parkinson's disease (PD) and Alzheimer's disease (AD) are the most prevalent neurodegenerative disorders affecting the aging of human brain. Several proteomics approaches help in the analysis of brain samples. Separation is done either directly on the protein basis using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), one-dimensional polyacrylamide gel electrophoresis (1D-PAGE), or comprehensive one-dimensional or multidimensional liquid phase based separation techniques (1D/MD-LC). For quantification analysis, several approaches, such as metabolic isotope labeling or chemical labeling are described. New developments in mass spectroscopy (MS) instrumentation focus on the methods that introduce as many peptide ions into the mass spectrometer as possible, as well as ways to manipulate the ion population so that the lower-abundance species can be measured exclusively in a complex mixture. It becomes more and more apparent that in the near future, the most powerful technology for the comprehensive analysis of complex protein mixtures will be a combination of multidimensional fractionation and advanced MS instrumentation.