Citrate synthase is a novel in vivo matrix metalloproteinase-9 substrate that regulates mitochondrial function in the postmyocardial infarction left ventricle

To evaluate the role of matrix metalloproteinase (MMP)-9 deletion on citrate synthase (CS) activity postmyocardial infarction (MI). We fractionated left ventricle (LV) samples using a differential solubility-based approach. The insoluble protein fraction was analyzed by mass spectrometry, and we identified CS as a potential intracellular substrate of MMP-9 in the MI setting. CS protein levels increased in the insoluble fraction at day 1 post-MI in both genotypes (p