The objective of this project is to discover mitochondrial protein biomarkers of atrial fibrillation (AF). Our research strategy is based on a comparative mass spectrometric (MS) analysis of
mitochondrial protein fractions isolated from lysates of left and right atrial tissue obtained from AF patients and non-AF control subjects. The experimental approach of online liquid chromatography-tandem mass spectrometry (LC-MS/MS) followed by database search and manual data and results evaluation was used to identify peptides and phosphorylated peptides from cardiac tissue mitochondria protein tryptic digests. Potentially differentially abundant peptides/proteins in right atria of AF patients v. controls, and in left v. right atria of AF patients,
were determined by spectral counting-based comparative analysis. The initial results of the study include several possibly differentially-abundant proteins and phosphoproteins with potential relevance to AF. Selected candidate biomarkers will be subjected to verification analyses using antibody- (reverse phase protein microarray, RPMA) and MS- (MRM) based analyses.