Solution conformation of endothelin, a potent vaso‐constricting bicyclic peptide A combined use1H 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 using1H NMR conformational constraints and distance geometry calculations. The conformation is constrained by two disulphide bridges between Cys1‐Cys11 and Cys1 Cys11 but the NMR data and computed conformers show additional helical structure between residues Leu4 and Cys11. Our results are compared with previous conflicting reports on the solution conformation on this peptide.