Tools for investigating peptide-protein interactions: peptide incorporation of environment-sensitive fluorophores through SPPS-based 'building block' approach

This protocol presents the synthesis and peptide incorporation of environment-sensitive fluorescent amino acids derived from the dimethylamino-phthalimide family. The procedure uses anhydride precursors of 4-dimethylaminophthalimide (4-DMAP) or 6-dimethylaminonaphthalimide (6-DMN), whose syntheses are described in a related protocol by these authors. In this study, the corresponding fluorescent amino acids can be readily obtained in Fmoc-protected form for convenient use as building blocks in solid phase peptide synthesis (SPPS). The time required to complete the procedure depends on the size and the number of peptides targeted. Alternatively, the chromophores can be incorporated directly after SPPS via on-resin derivatization of peptides, which is an option described in a related protocol by these authors.