Title
Effect of Covalent Interaction with Chlorogenic Acid on the Allergenic Capacity of Ovalbumin
Author
Yuqin Lu, Shuiming Li, Haoxie Xu, Tingting Zhang, Xiao Lin, Xuli Wu
Year
2018
Journal
Journal of Agricultural and Food Chemistry
Abstract
Ovalbumin (OVA) is a major allergen in avian egg white. The objective of this study was to investigate the conjugation of OVA and chlorogenic acid (CA) to reduce the allergenic capacity of OVA. OVA–CA conjugate was characterized by SDS-PAGE, MALDI-TOF-MS, fluorescence spectroscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy and circular dichroism analyses. Sites of the OVA–CA conjugate were identified by LC−MS/MS. CA conjugated with Lys20 and Lys17 in OVA, which resulted in the unfolding of OVA. ELISA and western blot assay indicated that the OVA–CA conjugate reduced the IgE binding capacity of OVA and the ability of the OVA–CA conjugate to activate histamine release was reduced. The decreased allergenic capacity of OVA was attributed to changes in the protein structure. Moreover, the CA binding site in OVA might directly shield the linear IgE epitope, thereby reducing the IgE binding ability. Also, the OVA–CA conjugate showed high antioxidant activity. OVA conjugated with CA may be a promising method of OVA hyposensitization.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Protein folding, Chemical stability, Biochemistry, Food science, Medicinal