Proteomic Analysis of Human Fetal Atria and Ventricle

In this study we carried out a mass spectrometry-based proteome analysis of human fetal atria and ventricles. Heart protein lysates were analyzed on the Q-Exactive mass spectrometer in biological triplicates. Protein identification using MaxQuant yielded a total of 2754 atrial protein groups (91%) and 2825 ventricular protein groups (83%) in at least 2 of the 3 runs with ≥ 2 unique peptides. Statistical analyses using fold-enrichment (>2) and p-values (≤ 0.05) selected chamber-enriched atrial (134) and ventricular (81) protein groups. Several previously characterized cardiac chamber-enriched proteins were identified in this study including atrial isoform of myosin light chain 2 (MYL7), atrial natriuretic peptide (NPPA), connexin 40 (GJA5), and peptidylglycine alpha-amidating monooxygenase (PAM) for atria, and ventricular isoforms of myosin light chains (MYL2 and MYL3), myosin heavy chain 7 (MYH7), and connexin 43 (GJA1) for ventricle. Our data was compared to in-house generated and publicly available human microarrays, several human cardiac proteomes, and phenotype ontology databases.