Identification of glycated peptides in human serum using LC-MS/MS: A comparison of data-dependent acquisition and Parallel reaction monitoring

Protein glycation is vital to aging and disease. However, glycated proteins are low-abundant in plasma, rendering them difficult to identify using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Many studies have analyzed glycated peptides with high reproducibility. Here, glycated peptides in human serum were analyzed by LC-MS/MS using data-dependent acquisition (DDA) and parallel reaction monitoring (PRM). Boronic acid (BA) enrichment of in vitro glycated human serum peptides was performed. BA enrichment identified the most glycated peptides, and the glycated peptides of the more diversified proteins, excluding albumin, were analyzed. In PRM, glycated albumin PSMs were the most common, and this method exhibited the best reproducibility. The results of this study could help compare methods for identifying glycation-related biomarkers.