Immunomodulatory Effect of Laccase/Caffeic Acid and Transglutaminase in Alleviating Shrimp Tropomyosin (Met e 1) Allergenicity

Abstract

This work aimed to investigate the effect of enzymatic cross-linking on the allergenic potential of shrimp tropomyosin (TM), Met e 1. The cross-linked TM with laccase (CL), laccase/caffeic acid (CLC and CLC + ), and transglutaminase (CTG and CTG + ) formed macromolecules and altered the allergen conformation. The IgG/IgE-binding potentials of the cross-linked TM were reduced as confirmed by Western blotting and ELISA. Enzymatic cross-linking improved the gastrointestinal digestibility and induced a lower level of degranulation in RBL-2H3 and KU812 cells. Moreover, cross-linked TM decreased anaphylactic symptoms, as well as reduced the serum levels of IgG1, IgE, histamine, tryptase, and mMCP-1. In spleen cells, CLC + and CTG + downregulated the Th2-related cytokines and upregulated IFN-γ and IL-10. These findings revealed that CTG + has shown more potential than CLC + in mitigating the allergenicity of TM by influencing the conformational structure, enhancing the digestibility, decreasing the cellular degranulation process, and positively modulating the Th1/Th2 immunobalance.

Enzymatic crosslinking and food allergenicity: A comprehensive review

“…LACs have been reported to oxidize tyrosine, tryptophan, and cysteine (Li et al, 2020;Karaki et al, 2016). Incorporation of phenolic molecules together with PPO can overcome the lack of surface-exposed tyrosine residues on the target proteins by providing free hydroxyl functional groups and other reactive sites (Ahmed et al, 2020;Lv et al, 2019).…”

“…Enzymatic crosslinking of dietary proteins can alter the conformational structures, surface properties, charge moieties, and molecular weights of proteins. Moreover, the enzymatic process assists in the modification of biological properties of allergenic proteins, including solubility, ligand binding, digestibility, antigenicity, and IgE binding potentials (Ahmed et al, 2019(Ahmed et al, , 2020Yuan et al, 2018). Two types of enzymatic methods are used currently to reduce the allergenic potential of food allergens.…”

“…Nonetheless, TYR-catalyzed crosslinking is based on the formation of quinones, whereas, LAC-catalyzed crosslinking reaction is reliant on free radicals and their subsequent reactions. Similarly, incorporations of low molecular weight phenolic compounds have been reported to improve the crosslinking efficacy of oxidative enzymes (Ahmed et al, 2020;Li et al, 2020). Transglutaminase (TG) is capable of catalyzing protein network formation by the introduction of glutamyl-lysyl isopeptide bonds between target proteins.…”

“…Enzymatic crosslinking has the potential to alter the primary, secondary, and tertiary structure of food allergens by site-specific modification of certain amino acid residues, resultantly form a high molecular weight polymerized allergens. Studies have shown that enzymatic crosslinking caused the loss of secondary structure of food allergens and unfolded the tertiary structure (Ahmed et al, 2020;Fei et al, 2016). The unfolding of food allergens could cause changes in the surface hydrophobicity due to the creation of hydrophilic or hydrophobic groups and aggregation of hydrophobic interactions (Ahmed et al, 2018;Tian et al, 2019).…”

Quantification of crustacean tropomyosin in foods using high‐performance liquid chromatography–tandem mass spectrometry method

“…Tropomyosin (TM) is the major allergen identified in crustaceans, having two identical subunits with molecular masses ranging from 35 to 38 kDa. TM shows stability to various food processing methods, such as high‐temperature processing, pasteurization, and grinding 3–6 . Crustacean products pose serious concerns for patients allergic to TM 7,8 .…”