Establishment and optimization of peptide biomarker screening model in diabetes in vitro by HPLC/ESI-TOF mass spectrometry

Diabetes mellitus is an incurable disease, so it is necessary to establish a model to screen biomarkers for early warning in order to minimize the likelihood of long-term complications. Currently, advanced glycation end products (AGEs) are considered to be biomarkers of many diseases, such as diabetes and its complications. In this study, a model for further proteomics study was established to analyze the glycation of HSA with ¹⁸O-labeling strategy. 30 peptides were randomly selected to optimize tryptic digestion and ¹⁸O-labeling condition by HPLC-ESI/TOF. The best tryptic digestion condition was: HSA:Trypsin=50:1, w/w for 20 h. The best ¹⁸O-labeling condition was to dilute urea to 1 M and adjust KH₂PO₄-K₂HPO₄ buffer pH to 6.0 to give a final labeling efficiency of 98.5±0.7%. The inter- and intra-day precisions and stability were satisfactory. This model was established and optimized for further quantitative proteomics study.