Elucidating the cleavage patterns of allergenic epitopes of Parvalbumin by L. helveticus fermentation through cell...

Parvalbumin (PV) is recognized as a primary allergen in fish. Previous studies showed that L.helveticus Lh191404 reduces the immunogenicity of Atlantic cod through fermentation, primarily by producing cell envelope proteinase (CEP) to hydrolyze the substrate. However, the cleavage sites of allergenic epitopes during fermentation remained unclear. Peptidomic analysis revealed that the enzymatic hydrolysis process can serve as a proxy for the fermentation process to some extent. Both the fermentation and enzymatic hydrolysis groups contained cleavage sites located within the epitopes. Computer simulations demonstrated that the flexible region of PV is the optimal binding site for CEP. Ala4, Asp52, Gln69, Arg76, and Ala77 located within this flexible region were the cleavage sites in a simulated fermentation environment. The majority of the predicted cleavage sites aligned closely with those observed experimentally. MD simulation offers a framework for the targeted screening of LABs that can compromise the structural integrity of target proteins.