Proton n.m.r. investigation of conformational influence of penicillamine residues on the disulfide ring system of opioid receptor selective somatostatin derivatives

Int J Pept Protein Res. 1988 Feb;31(2):192-200. doi: 10.1111/j.1399-3011.1988.tb00022.x.

Abstract

Three cyclic disulfide analogs related to somatostatin, D-Phe(1)-cyclo(Cys(2)-Tyr(3)-D-Trp(4)-Lys(5)-Thr(6)-Xxx(7))-Thr(8)- NH2 (where Xxx = L-Pen 1; L-Cys 3; or D-Pen 4) were examined in DMSO-d6 by one- and two-dimensional proton n.m.r. spectroscopy in order to analyze the conformational influence of the position-7 residue on the 20-membered disulfide ring. From these studies it was concluded that all three analogs maintain a beta II' turn solution conformation for the core tetrapeptide -Tyr(3)-D-Trp(4)-Lys(5)-Thr(6)-. However, the disulfide conformation differs in the analogs, with 1 and 3 having a left-handed and 4 a right-handed disulfide chirality.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Disulfides
  • Magnetic Resonance Spectroscopy / methods
  • Models, Molecular
  • Penicillamine*
  • Protein Conformation
  • Receptors, Opioid / metabolism*
  • Somatostatin / analogs & derivatives*
  • Structure-Activity Relationship

Substances

  • Disulfides
  • Receptors, Opioid
  • Somatostatin
  • Penicillamine