Thirteen NIH-funded investigators request funds for a Finnigan LTQ linear ion trap MS, equipped with a complete Dionex UltiMate nano-LC system, a nano- ESI source, and a data analysis workstation with BioWorks/TurboSEQUEST/SALSA, for high sensitivity proteomics and post-translational modification analyses. The potential to achieve proposed research goals will be substantially enhanced by the 10-fold sensitivity increase of the LTQ compared to our current LCQ DECA. No other LTQ exists in the greater Albany area, nor is there any instrument with the MS/MS sensitivity for proteomics or LC-MS/MS/MS capability for peptide phosphorylation analyses. Award of the LTQ will permit proteomics analyses on many projects that are well beyond our current sensitivity limits. Specific research areas include: regulation/ modification of cytochrome P450 enzymes in the human respiratory tract; identification of human ovarian autoimmune antigens causing infertility; M. tuberculosis and Yersinia pestis biology; metal-induced immunopathology; and human lysosomal protein expression and methotrexate resistance. Post-translational modification and phosphorylation determination projects include: Spisula-derived centrosome complex proteins; the motor protein, dynein; human vascular smooth muscle proteins; motility proteins of the human pathogen, Treponema denticola; and growth factors and signal transduction receptors in colon cancers. Currently, all listed co-investigators collaborate with the Wadsworth Mass Spectrometry/Proteomics Core. The Core Director (the Principal Investigator) has extensive experience in protein mass spectrometry and the management of a multi-instrument, multi-user facility. The LTQ MS will be integrated into this core, which has a record of both routine analyses and research collaborations with investigators at Albany Medical College, SUNY Albany, Rensselaer Polytechnic Institute, and Roswell Park and will benefit other NIH-funded research programs at these institutions.