Exploration of structure-activity relationship between IgG1 and IgE binding ability and spatial conformation in ovomucoid with pulsed electric field treatment

Abstract

Ovomucin (OVM) is one of the most main allergens in egg white, which limits the application of egg in the field of food processing. In this study, the effect of pulsed electric fields (PEF) on the IgG1 and IgE binding capability and the composition changes of OVM was studied by indirect competitive ELISA, SDS-PAGE, Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD) spectroscopy, contact angle meter, fluorescence spectrophotometer and scanning electron microscopes (SEM). The results suggested that PEF treatment couldsignificantly reduce the IgG1 and IgE binding capacity of OVM, especially under the condition of 30 kV/cm. PEF treatment could cause partial unfolding of the protein, which was attributed to the destruction of the epitope structure that binds to IgG1 and IgE in OVM. Results indicated that PEF treatment significantly changed the primary structure, secondary structure and tertiary structure of the protein. Specifically, the secondary structure of the protein was partially unwound, and hydrophobic amino acids were exposed after PEF treatment. In addition, we observed that the microstructure of the OVM also changed significantly after PEF treatment.