Discovery of Mitochondrial Protein Biomarkers of Atrial Fibrillation Using Unique Human Tissue Samples

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.