SOLUTION STRUCTURE OF ENDOTHELIN-3 DETERMINED USING NMR-SPECTROSCOPY

The aqueous solution structure of the 21-residue vasoactive peptide hormone endothelin-3 has been determined using high-resolution NMR spectroscopy, A total of 177 proton-proton distance measurements and 5-chi-1 dihedral angle constraints derived from NMR spectra were used to calculate the structure using a combination of distance geometry and dynamical simulated annealing calculations. The calculations reveal a highly ordered, compact conformation in which a helical region extending from K9 to C15 lies in close apposition with the C-terminal hexapeptide; this interaction seems to be largely driven by hydrophobic interactions. Structure-activity studies are interpreted in terms of the conformational features of the calculated endothelin-3 structure.