Phosphoproteomics evaluation of the effect of GLP-1 on the porcine pacemaker

GLP-1 induces an increase in heart rate, but its mechanism remains elusive. We used a phosphoproteomic approach to evaluate the effect of GLP-1 on the porcine sinus node. Tissue samples from the sinus node region and left ventricle were collected from eight animals following a 60-minute infusion with either GLP-1 or saline. We employed a tandem mass tag (TMT) labeling strategy to multiplex samples, enriched for phosphorylated peptides by titanium dioxide chromatography, and pre-fractionated the resulting peptide pool prior to LC-MS/MS measurements on an Orbitrap Ascend Tribrid mass spectrometer.