Comparison of Fibrillation Ability, Self-Assembly Behavior and Structural Characteristics of Wheat Gluten and Its Components Amyloid Fibrils

This study has investigated the fibrillation ability, self-assembly behavior, and structural characteristics of amyloid fibrils formed from wheat gluten and its components (glutenin and gliadin) through enzymatic hydrolysis and hydrothermal treatment. Trypsin hydrolysis induced the exposure of aggregation-prone regions, particularly in gliadin hydrolyzed peptides, enabling rapid nucleation within 0.53 h and elongation into flexible fibrils (up to 4.86 μm) at the highest growth rate (119.88 au/h). Due to their intricately folded conformations, glutenin hydrolyzed peptides required to overcome the highest energy barrier (99.14 kJ mol-1) for nucleation. The lowest hydrophobicity index (168.45) and Zeta potential (-19.6 mV) of glutenin hydrolyzed peptides conferred diminished fibrillation propensity, ultimately yielding short (2.77 μm) flexible fibrils. Fibrils derived from gluten hydrolysates exhibited the highest β-sheet content (50.05%), the largest particle size (434.85 nm), and the greatest fibril length (5.72 μm). Gluten amyloid fibrils displayed morphological polymorphism, potentially resulting from synergistic interactions between glutenin and gliadin, including template-induced assembly and disulfide cross-linking. This study reveals component-level formation mechanisms of wheat gluten amyloid fibrils, with potential implications for food applications.