Glycation of heme-protein, “myoglobin” by 3-deoxyglucosone: Implications in immunogenicity

The Reactive carbonyl species (RCS) like, 3-deoxyglucosone (3-DG) is a highly reactive intermediate of the glycation reaction which may result into the formation of protein advanced glycation end-products (AGEs), like myoglobin-AGEs (Mb-AGEs) which further lead to the structural perturbations. In the present work, we studied the glycation of myoglobin (Mb) by physico-chemical techniques and the resulting immunogenicity by ELISA techniques. The level of free lysine and arginine determined was found to be significantly decreased indicating the establishment of the glycation reaction. The glycated myoglobin (G-Mb) shows the increased absorbance at 280 nm and enhanced fluorescence emission at 350 nm excitation wavelengths. The levels of ketoamine and hydroxymethylfurfural (HMF) were recorded to be enhanced in G-Mb when compared to its native conformer. Furthermore, the New-Zealand white female rabbits immunized with native and its glycated analogue ‘G-Mb’ induced high titer antibodies as compared to the native one.