Study on the stability and allergenicity of Litopenaeus vannamei shell protein

ObjectiveTo explore the stability and allergenicity of Litopenaeus vannamei shell protein， identify the categories of allergenic proteins， and predict the antigen epitopes.MethodsAfter extracting crude protein from shrimp shells using salt precipitation， L. vannamei shell protein was treated sequentially with heat， acid/base， and simulated gastric digestion， followed by electrophoretic analysis. Serological method was used to identify bands that L. vannamei shrimp shell protein bind specifically to antibodies from the serum of allergic patients， and then the bound protein bands were analyzed using liquid chromatography-tandem mass spectrometry. Bioinformatics analysis were employed for allergenicity analysis and B-cell linear epitope prediction， based on mass spectrometry results.ResultsL. vannamei shell protein was relatively stable to heat， however it was unstable in acidic and alkaline conditions and was easily digested by simulated gastric fluid. The molecular weights of the proteins in L. vannamei shell that specifically bound to antibodies from allergic patients were approximately 75 kDa. The main potential allergenic proteins present in L. vannamei shells were hemocyanin and β-1，3-glucan binding protein.ConclusionThe existence of hemocyanin in the shells of L. vannamei， which may be an allergenic protein with high molecular weight and exhibited thermal stability but being easily digested by gastric juic. This study provides evidence for the allergenicity evaluation of L. vannamei shell products and the necessity for their low-allergen processing.