Exploring the self-assembly mechanisms of wheat gluten polypeptide hydrogels: Synthesis and characterization

Abstract

The purpose of this study was to demonstrate a mild enzymatic method for the large-scale production of nano-scale self-assembled peptide hydrogels (WGP-M, average molecular weight 3697.86 Da) with strong hydrogel-forming ability from gluten. This work aims to provide new insights into the molecular characteristics and aggregation mechanisms of these plant-derived hydrogels. We observed that the Zeta potential of WGP-M decreased to −17.7 mV, indicating reduced electrostatic repulsion, while the particle size increased to 626.21 nm, reflecting the formation of a stable hydrogel network. The spatial network microstructure was clear, and the hydrogel exhibited excellent texture and rheological properties. Further analysis revealed that the formation of peptide hydrogels was primarily driven by hydrophobic interactions, sulfhydryl (7.48 μmol/g) and disulfide (1.31 μmol/g) bond exchanges, and hydrogen bond interactions. Using proteomics combined with molecular docking simulations, we demonstrated the positive influence of amino acid molecular characteristics and arrangement on hydrogel formation, providing a more intuitive understanding of this process. In summary, this study not only establishes an efficient pathway for producing self-assembled peptide hydrogels from plant proteins but also advances our understanding of the fundamental mechanisms underlying their formation.