PROBING PROTEINS AND DIFFERENTIATING THEIR NATIVE AND DENATURED STATES WITH AGGREGATION-INDUCED EMISSION FLUOROGEN

The tertiary 3D structures of proteins determine their unique functions. Perturbation of their native state including denaturation may cause loss of the protein functions. In this work, water-soluble tetraphenylethylene (TPE) fluorophore, sodium 1,2-bis[4-(3-sulfonatopropoxyl)phenyl]-1,2-diphenylethene (BSPOTPE), with aggregation-induced emission (AIE) characteristics is utilized as a fluorescent probe for protein detection and for differentiating their folding modes. Owing to hydrophobic interaction between the proteins and BSPOTPE, it provides a fast and simple method to differentiate the native and denatured states of the proteins through monitoring fluorescence change in solution and PAGE gels. Six proteins are chosen as model proteins in the study. Among them, cytochrome c shows distinctive behavior to other proteins due to the presence of heme group. A comprehensive study of cytochrome c and human serum albumin is carried out in this work.