Mechanochemical responses in β-lactoglobulin-based hydrogels: protein unfolding and chemical modification through compression

Abstract

Abstract In this study, we investigated mechanical protein unfolding in hydrogels composed of cross-linked β-lactoglobulin. The hydrogels were prepared by the reaction of β-lactoglobulin with polyethylene glycol tethering activated esters at both ends. Compressing the hydrogels enables the modification of β-lactoglobulin in the gel with fluorophores such as a pyridyl disulfide-containing fluorescent protein and a tetraphenylethene derivative. This finding indicates that the unfolding triggered by hydrogel compression induces exposure of a reactive cysteine residue in the protein.