Self-assembly and hydrogelation properties of egg white-derived peptides

Abstract

Functional foods are gaining traction as a source of peptides possessing hydrogelation properties. Analysis of peptides (n=429) in egg white protein hydrolysates resulted in the identification of six peptides: IFYCPIAIM, NIFYCPIAIM, VLVNAIVFKGL, YCPIAIMSA, MMYQIGLF, and VYSFSLASRL as prominent self-assembly candidates based on prediction of their aggregation-prone segments. The objective of this study was to characterize the hydrogel formed via self-assembly of the peptides. Of the six peptides studied, NIFYCPIAIM and MMYQIGLF showed promising self-assembly and hydrogelation properties. Thioflavin T kinetics indicated that NIFYCPIAIM possesses the strongest self-assembly property, confirmed by dynamic light scattering which indicated the largest average particle diameter was achieved after 24 hours. Rheological characterization indicated that all six peptides possessed viscoelastic pseudoplastic properties and some were able to regain some level of viscosity following the exertion of shear stress. Finally, transmission electron microscopy of the six peptides showed the development of fibrillar structures of varying morphologies after 24 hours. The remarkable difference in self-assembly and hydrogelation properties of NIFYCPIAIM, IFYCPIAIMSA and YCPIAIMSA, which share a common sequence YCPIAIM, indicate the importance of amino acid sequence in the formation and property of peptide hydrogels. Identification of the egg white-derived peptides with hydrogelation properties shows a promising future for the use of functional foods in applications of drug delivery systems and tissue engineering, in the food, pharmaceutical, cosmetics, and biomedical sectors.