Casein (CN) is the primary factor leading to allergic reactions in infants to bovine milk, severely limiting the intake of bovine milk formula by allergic infants. This study investigates the conformational changes and regulation of linear epitopes during the hydrolysis of CN by five proteases derived from microbial and plant sources using multiple spectroscopic techniques combined with LC/MS-MS. The results showed that the IgE inhibition rates for SD (subtilisin hydrolysate), PD (papain hydrolysate), BD (bromelain hydrolysate), KD (proteinase K hydrolysate), and FD (ficin hydrolysate) were 43.19%, 41.99%, 35.45%, 48.15%, and 14.80%, respectively. The differences in antigenic residues remaining after hydrolysis by different proteases mainly result from the varying degrees of structural alteration of CN and the hydrolysis allergic epitope regions. This study provides theoretical basis for understanding the mechanism by which proteases reduce the allergenicity of CN. It also offers new insights into the development of multienzyme combinatorial hydrolysis strategies.
Read full abstract