Composition, structural configuration, and antigenicity of Atlantic cod (Gadus morhua) tropomyosin.

Yaqi Zhao, Xingyi Jiang, Chunya Tang, Qinchun Rao

Food chemistry 2023 Jan 15

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Tropomyosin, a myofibrillar muscle protein, has been recognized as a finfish allergen. In this study, tropomyosin from Atlantic cod fillets (Gadus morhua, CTM) was purified using a two-step purification strategy (isoelectric precipitation and anion-exchange chromatography). CTM structural configuration in two sample matrices (impure and pure) were elaborated using different polyacrylamide gel electrophoresis (native, non-reducing, and reducing PAGE). Their corresponding immunoblots were conducted to investigate CTM antigenicity under three conditions. Overall, CTM retained solubility, integrity, and antigenicity after heat treatment. Three CTM monomeric α-type isoforms (33 kDa) were identified using two-dimensional PAGE. Under native condition, the vast majority of CTM existed in the disulfide-reduced dimeric form (66 kDa). Under non-reducing condition, sodium dodecyl sulfate (anionic surfactant) broke CTM dimers, leaving monomers and disulfide-induced tetramers. Under reducing condition, β-mercaptoethanol (thiol reducing agent) dissociated disulfide-linked CTM tetramers (132 kDa) into monomers (33 kDa). CTM retained antigenicity regardless of structural configuration under different conditions. Copyright © 2022 Elsevier Ltd. All rights reserved.

Citation

Yaqi Zhao, Xingyi Jiang, Chunya Tang, Qinchun Rao. Composition, structural configuration, and antigenicity of Atlantic cod (Gadus morhua) tropomyosin. Food chemistry. 2023 Jan 15;399:133966