Abstract: Silver carp parvalbumin (PV) was acylated with octenyl succinic anhydride (OSA). The structural and allergenicity changes of PV before and after modification were determined using spectroscopy, mass spectrometry (MS), and an indirect enzyme-linked immunosorbent assay (ELISA). The results indicated that covalent binding occurred between OSA and PV, which led to an increase in the molecular mass of PV. Spectroscopic analysis revealed that after acylation modification, the ultraviolet (UV) absorbance and intrinsic fluorescence intensity of PV decreased, and the free sulfhydryl content significantly fell. MS showed that Lys39, Lys84, Lys88, Lys97, and Ser37 were the primary acylation sites for OSA. Allergenicity analysis results demonstrated that the immunoglobulin (Ig)G/IgE binding capacity of acylated PV was significantly reduced compared with that of native PV. In conclusion, acylation modification reduced the allergenicity of PV by disrupting its allergenic epitopes. Therefore, OSA-based acylation modification is an effective technique for reducing the allergenicity of allergens.

Key words: parvalbumin; octenyl succinic anhydride; acylation modification; structure; allergenicity