Core C: Summary/Abstract The proteomics and analytical biochemistry core C provides essential technical support for all three of the projects in our program. The main functions of Core C are to provide: (i) support for determining post- translational modifications (PTM) in cardiac tissue (human from Core B, rodent and rabbit) with an emphasis on sarcomeric proteins utilizing 2D-DIGE, 2D-PAGE and Pro-Q staining; (ii) separation of cardiac proteins or peptides in solution by OFFGEL fractionation; (iii) mass spectrometric (MS) analysis support to identify proteins and their (PTMs) along with multiple reaction monitoring (MRM) for targeting specific PTMs; (iv) support for identifying reactive oxygen species (ROS) induced protein modifications by Oxyblot, 2D-diagonal gels, glutathionylation Western blot assays and biotin switch assays; (v) support for determining global changes in both protein abundance and PTMs by iTRAQ/TMT labeling of either the whole proteome or sub-proteomic fractions. Core C also prepares sub-proteomic fractionation of the sarcomeric proteins or whole heart homogenates for proteomic characterization. To ensure productivity and progress, Core C support provides state-of-the-art facilities and equipment such as the Orbitrap Velos Pro and the AB Sciex 6500 Q-TRAP for advanced proteomic analysis required by all projects in the program. Core C support is critical to approach for aims in each of the projects and thus is indispensable for the overall success of the program.