An improved solid-phase synthesis of resonance energy transfer fluorescent peptides and depsipeptides employing the EDANS/DABCYL donor-acceptor pair

Abstract

Fluorescent peptide substrates of the resonance energy transfer type, employing thedonor–acceptor pair 5-[(2′-aminoethyl)amino]naphthalene sulphonic acid(EDANS) and 4-[[4′-(dimethylamino)phenyl]azo]benzoic acid (DABCYL), are widelyused for continuous monitoring of the activity of various proteases. We describe here aflexible synthetic scheme which allows the synthesis of peptides having EDANS andDABCYL in any position of the sequence; the synthesis is entirely performed on solid phasewith standard methods and makes use only of EDANS, DABCYL and commercially availableamino acid derivatives. Moreover, we show that our scheme can be equally applied to thesynthesis of EDANS/DABCYL-derivatised depsipeptides.