Proteome characterization of mouse brain mitochondria using electrospray ionization tandem mass spectrometry.

Mitochondria are responsible for several essential functions, including apoptosis, iron-sulfur cluster assembly, and several important catabolic pathways in mammalian cells. Characterization of the mitochondrial proteome may therefore be extremely useful for identification and validation of targets for therapeutic treatment of human diseases, including aging and age-related disorders, diabetes, and obesity. While capillary isotachophoresis (CITP) has been introduced for on-capillary analyte preconcentration prior to electrophoretic separation, the application of transient CITP/capillary zone electrophoresis (CZE) to selectively enrich and resolve trace amounts of proteins/peptide is employed in an effort to expand mitochondrial proteome coverage in mammals. In this study, a total of 2095 distinct mouse SwissProt protein entries are identified from synaptic mitochondria isolated from mouse brain, corresponding to 50% and 76% coverage of the Maestro and MitoP2 mitochondrial reference sets, respectively. The increased coverage of mouse mitochondrial proteome further reveals the top 17 biosynthetic and metabolic pathways in synaptic mitochondria using the Ingenuity Pathway Analysis.