This NCRR shared instrumentation proposal seeks funding for the purchase of an integrated HPLC MS/MS system at the Buck Institute for Age Research consisting of an Applied Biosystems/Sciex QTRAP 5500 triple quadrupole linear ion-trap mass spectrometer equipped with a nano-electrospray ionization source mass spectrometer and an Eksigent/Tempo nano-capillary high performance liquid chromatograph (HPLC). This instrument will be housed and maintained at the Buck Institute's Chemistry &Proteomics Core and will serve a minimum 14 different research projects, 3 of which involve researchers at outside institution, i.e., UCSF, Gladstone Institute and the University of Iowa. In brief, we propose to operate this instrument exclusively for the targeted quantitation of peptides derived form various proteins of interest that are obtained from various biological materials relevant to human health, including mouse and human tissues, cell lines, human plasma sample, and infection organisms. Overall, these analyses will focus primarily on the requested QTRAP 5500's ability to perform multiplexed quantitation of peptides via multiple reaction monitoring (MRM). In addition, we will use this new instrument to identify and quantify a pre-select set of biologically important enzymatic and non-enzymatic posttranslational modifications using neutral loss scanning and positive/negative mode switching capabilities. The data obtained from the requested instrument will be critical to understand various disease models and paradigms. Indeed, these research projects encompass the study of neurodegenerative diseases processes such as Huntington's, Parkinson's and Alzheimer's disease, the identification of novel protein targets or biomarkers for the early detection of cancer, examining the role of mitochondrial dysfunction in aging and age-related diseases, and analysis of the role of biofilms in human bacterial pathogenesis. PUBLIC HEALTH RELEVANCE: New instrumentation is requested that will serve a variety of research projects at the Buck Institute for Age Research and neighboring institutions. The requested mass spectrometer system will allow us to carry out a variety of research projects that encompass the study of neurodegenerative (Huntington's, Parkinson's and Alzheimer's disease), the identification of novel biomarkers for the early detection of cancer, determining the role of mitochondrial dysfunction in aging and age-related diseases, and the analysis of the bacterial biofilms that form in some human diseases, such as chronic ear infections and pelvic inflammatory disease.