Identification of AGE-precursors andAGE formation in glycation-induced BSA peptides

The glycation of BSA leads to protein/pepticle modifications that result in the forTnation of AGEs. AGEs react with the amino groups of N-terminal amino acid residues, particularly arginine and lysine residues. Enhanced AGE formation exists in the blood and tissues of diabetics, as well as in aging and other disorders. The Identification of AGEs is of great importance. Mass spectrometry has been applied to identify and structurally elucidate AGEs. Here, we report on the identification of AGE- pepticles and AGEprecursors based on relative mass changes as a result of specific AGE foanation. HPLC-ESIMS, ESI-MS/MS, and the Mascot database were used. The relative mass changes due to the specific type of AGE formation were added to the identified pepticles followed by a manual search of the glycated samples, which resulted in the identification of seven pepticles for the formation of five AGEs, namely CML, pyrraline, imiclazolone A, imiclazolone B, and AFGP. Four glycated pepticles (FPK, ECCDKPLLEK, IETMR, and HLVDEPQNLIK) were identified in the formation of AGE-precursors.