As an invaluable tool for biomedical research, the green fluorescent proteins (GFPs) make tumor cells, amyloid plaques, and pathogenic bacteria equally visible. Here, inspired by the chromophore of GFPs, we constructed a tyrosine-based peptide that show green luminescence in the aggregation state. Similar to the optical property of GFPs, the tyrosine-based peptidyl nanoparticles are stabilized by intermolecular hydrogen bonding and emit fluorescence when the Tyr residues bear phenolic anions. In addition, the tyrosine-based peptide is cell-permeable and endosome-escaped when conjuncted with the GPGR motif of human immunodeficiency virus and can be used for stable cell imaging due to its excellent photostability, pH-sensitivity and biocompatibility in physiological conditions. The results provide a promising pathway to construct peptidyl bioluminescent agents for biomedical applications.
Keywords: cell imaging; fluorescence; green fluorescent protein; self-assembly; tyrosine.