Study on the mechanism of targeted regulation of casein linear epitopes by three animal-derived proteases under the optimal antigen inhibition rate conditions

Casein (CN) is the major family of proteins in milk and can cause allergic reactions in some infants and children. This study investigated the regulatory mechanisms of three animal-derived proteases on allergenic epitopes. The results showed that all three proteases effectively reduced the antigenicity of CN. After hydrolysis, the secondary structure of CN underwent a conformational transition from α-helix to β-turn. Based on peptidomics analysis, the allergenic epitopes of αs1-CN at positions 91–110, 131–151, 166–180 and 188–201 were effectively cleaved by pepsin, and the allergenic epitopes of β-CN at positions 60–69, 139–158 and 182–194 were effectively cleaved by pancreatic elastase.