Construction of protein hydrogels with antibacterial activity by interaction of β-lactoglobulin amyloid fibrils with epigallocatechin-3-gallate

Assembly of proteins into flexible biocolloids, nanorods and amyloid fibrils with high aspect ratio, has emerged as a popular templating strategy for construction of high-end technological materials. This study looked into how interactions between fibrillar proteins (pH 2.0, 90 °C for 10 h) and polyphenols affect the creation of heat-set protein hydrogels. Multi-spectroscopic methods as well as computer simulations suggested that the main interaction between fibrillar β-lactoglobulin (β-Lg) and (−)-epigallocatechin-3-gallate (EGCG) was hydrogen bonding. Such interaction could induce the association of β-Lg fiber, which was essential for forming gel-like structures. The β-Lg fiber hydrogel formed when the pH was roughly 6.0 and the protein concentration was raised to 2%. Additionally, it was found that the rheological and textural properties of the hydrogels could be modulated by altering the polyphenol concentration. Functionally, the EGCG-β-Lg amyloid fibril hydrogels exhibit strong activity against Escherichia coli and Staphylococcus aureus by causing them membrane disintegration. In combination with the non-toxic in human cell lines, this work constructed the protein hydrogels which could be employed in biomedical engineering.