Solution structure of dynorphin A (1-17): a NMR study in a cryoprotective solvent mixture at 278 K

Dynorphin A the endogenous agonist for the kappa opioid receptor, has been studied by NMR spectroscopy in methanol, acetonitrile, DMSO and in mixtures of hexafluaroacetone/water and DMSO/water. NMR data in the DMSO/water cryo mixture at 278 K are consistent with a conformer in which the N-terminal pa rt, like the corresponding message domain of enkephalins, is poorly ordered , whereas the C-terminal part is folded in a loop centred around Pro(10). T he folded structure of the C-terminal part [address moiety] may shed light on the role of the essential residues Arg(7), Lys(11) and Lys(13). Copyrigh t (C) 1999 European Peptide Society and John Wiley & Sons, Ltd.