Insight into the function of the key residues in the binding clefts of the substrate with CBM4-2 of xylanase Xyn10A by molecular modeling and free energy calculation

Combining experimental techniques with molecular dynamics to investigate the impact of different enzymatic hydrolysis of β-lactoglobulin on the antigenicity reduction

β-Lactoglobulin (β-LG) is one of the major food allergens. Enzymatic hydrolysis is a promising strategy to reduce the antigenicity of β-LG in industrial production. The relationship between the cleavage sites of β-LG by protease and its antigenic active sites were explored in this study. Molecular docking and molecular dynamics (MD) were used to analyze the active sites and interaction force of β-LG and IgG antibody. Whey protein was hydrolyzed by four specific enzymes and the antigenicity of the hydrolysates were determined by ELISA. The results of MD showed that the amino acid residue Gln155 (-4.48 kcal mol^-1) played the most important roles in the process of binding. Hydrolysates produced by AY-10, which was the only one with specificity towards cleavage sites next to a Gln, had the lowest antigenicity at the same hydrolysis degree. Antigenicity decrease was related to the energy contribution of the cleavage site in the active sites.