Solution conformation of endothelin, a potent vaso-constricting bicyclic peptide A combined use 1H NMR spectroscopy and distance geometry calculations

Abstract

The solution structure of endothelin 1, a newly discovered potent bicyclic peptide vaso-constrictor agent, has been investigated using 1H NMR conformational constraints and distance geometry calculations. The conformation is constrained by two disulphide bridges between Cys 1-Cys 11 and Cys 1 Cys 11 but the NMR data and computed conformers show additional helical structure between residues Leu 4 and Cys 11. Our results are compared with previous conflicting reports on the solution conformation on this peptide.