Investigation of the Mechanism of Conformational Alteration in Ovalbumin as Induced by Glycation with Different Monoses through Conventional Spectrometry and Liquid Chromatography High-Resolution Mass Spectrometry.

Glycation between ovalbumin (OVA) and different monoses under mild dry heating at 37 °C was studied. The content of free amino groups decreased dramatically, and the conformational changes based on fluorescence and circular dichroism spectra were evident in glycated OVA. The glycated sites and the average degree of substitution per peptide molecule per site were determined using liquid chromatography high-resolution mass spectrometry. Lysine and arginine were the predominant glyaction sites, in which Lys207 was a relatively reactive site for glycation in all of the conjugates. In general, the extent of glycation of aldose was higher, and its alterations on the steric layouts of protein were more drastic than those of ketose. The configuration of hydroxyl groups at C-4 in sugar epimers might be important for the glycation reactivity and conformational modification in the glycated proteins. These insights would have important implications for the creation of sweetened food products with desirable structures and excellent quality control.