Evidence for beta-turn structure in model peptides reproducing pro-ocytocin/neurophysin proteolytic processing site

Biochem Biophys Res Commun. 1990 May 16;168(3):1066-73. doi: 10.1016/0006-291x(90)91138-i.


The structural organization of small peptides reproducing the amino acid sequence of the common ocytocin/neurophysin precursor around the LysArg cleavage locus was investigated by a combination of spectroscopical techniques. In water both circular dichroism and [1H] NMR spectra indicated that these peptides adopted a random conformation. Evidence for folded structures was obtained when these compounds were placed in a membrane-like environment i.e. 40 mM SDS in phosphate buffer or trifluoroethanol. Whereas the CD spectra indicated the formation of various types of beta-turn in rapid equilibrium, measurements of NH temperature coefficients and Nuclear Overhauser Effects by 400 and 500 MHz NMR revealed the existence of contacts and of a folded conformation. These observations are discussed in relation with previous hypothesis made on the secondary structure organization of the proteolytic processing site of polypeptide hormone precursors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Circular Dichroism
  • Magnetic Resonance Spectroscopy
  • Models, Chemical
  • Molecular Sequence Data
  • Neurophysins / metabolism*
  • Oligopeptides / chemical synthesis*
  • Oligopeptides / metabolism
  • Oxytocin / analogs & derivatives*
  • Oxytocin / metabolism
  • Peptide Hydrolases / metabolism*
  • Protein Conformation


  • Neurophysins
  • Oligopeptides
  • Oxytocin
  • oxytocin, Gly-Lys-Arg-
  • Peptide Hydrolases