Evaluation of glycation reaction of ovalbumin with dextran: glycation sites identification by capillary liquid chromatography coupled with tandem mass spectrometry

Abstract An important relationship exists between the changes in glycation sites and structure of proteins. A combination of liquid chromatography and tandem mass spectrometry was used to identify the glycation information from ovalbumin (OVA) after dextran (Dex) conjugation under water heating (WH) or microwave heating (MH) conditions. After Dex conjugation, 12 O-linked glycation sites were identified in the OVA–Dex–MH conjugates, whereas 6 O-linked, 2 N-linked glycation sites were detected in the OVA–Dex–WH conjugates. These findings indicate that the amino acids at different positions in OVA molecular structure have different glycation reactivity under MH or WH induction systems. In addition, β-sheet and β-turn structures showed high glycation reactivity. The increased surface hydrophobicity of OVA–Dex conjugates was possibly attributed to the glycation sites that were mainly found in hydrophilic amino acids. Our study provides useful information for the glycation mechanism research of OVA and Dex.