Opioid peptides in micellar systems: conformational analysis by CD and by one-dimensional and two-dimensional 1H-NMR spectroscopy.

beta-Endorphin has been studied in SDS micelles by one- and two-dimensional nmr spectroscopy (1D and 2D nmr), and to explore the influence of peptide length and composition on the polypeptide structure, the investigation was extended to a number of fragments. The nmr results are compared with those obtained from CD experiments and discussed in terms of a secondary structure that involves the central region of beta-endorphin.