Heterologous amyloid fibril complexes formed by rice glutelin and soy protein: Assembly behavior and physicochemical properties

The low fibrillation efficiency of rice glutelin (RG) and the strong aggregation tendency of soy protein isolate (SPI) limit their practical applications. This study investigated RG/SPI co-fibrillation behavior to elucidate the structural features and physicochemical properties of the resulting heterologous amyloid fibrils. Results demonstrated that the 5:5 RG/SPI mixture achieved a 37.31 % higher fibril conversion rate than RG alone. Furthermore, increasing RG proportion mitigated the aggregation of SPI fibrils, enhancing dispersion uniformity. Structural analysis revealed that all samples developed more ordered β-sheet structures after fibrillation. Notably, the cross-β-sheet structure in heterologous amyloid fibrils was more compactly arranged than in single-amyloid fibrils. The viscosity, storage modulus (G′) and loss modulus (G″) of heterologous fibrils were lower than those of single-amyloid fibrils, improving the fluidity of samples. In conclusion, the high conversion rate and low aggregation tendency of heterologous amyloid fibrils are expected to play a more significant role in enhancing the efficiency of bioactive delivery and improving the performance of functional materials.