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Insight into the Mechanism of Reduced IgG/IgE Binding Capacity in Ovalbumin as Induced by Glycation with Monose Epimers through Liquid Chromatography and High-Resolution Mass Spectrometry
journal contribution
posted on 2020-05-21, 16:18 authored by Yipeng Yang, Guangxian Liu, Zongcai Tu, Hui Wang, Yueming Hu, Jihua Mao, Jingjing ZhangOvalbumin (OVA) is one of the major
food allergens in hen eggs.
In this work, it was demonstrated that glycation with d-glucose
and its epimers, including d-mannose, d-allose, d-galactose, and l-idose, could effectively attenuate
the IgG/IgE binding of OVA, which was attributed to the covalent masking
by sugars and to its structural changes. The glycation sites were
determined, and their average degree of substitution was found using
liquid chromatography coupled with high-resolution mass spectrometry.
Fluctuations in OVA conformation were monitored by conventional spectrometry.
Compared to those of OVA-Man and OVA-Glu, OVA-All, OVA-Gal, and OVA-Ido
showed a higher glycation extent, and the alterations on their steric
layouts were more drastic, suggesting that the configuration of hydroxyl
groups at positions C-3, C-4, and C-5 in sugars might be important
for the glycation reactivity; as such, their capabilities in binding
with IgG/IgE decreased more significantly. Attempts were made to provide
valuable information for in-depth understanding of the differences
in biochemical functionality among epimeric sugars. These insights
would be helpful for designing sweetened food products with a desirable
level of safety.