The Effects of C-terminal Modifications on the Opioid Activity of [N-benzylTyr(1)]dynorphin A-(1-11) Analogues

J Med Chem. 2009 Nov 12;52(21):6814-21. doi: 10.1021/jm900715m.

Abstract

Structural modifications affecting the efficacy of analogues of the endogenous opioid peptide dynorphin (Dyn) A have focused on the N-terminal "message" sequence based on the "message-address" concept. To test the hypothesis that changes in the C-terminal "address" domain could affect efficacy, modified amino acids and cyclic constraints were incorporated into this region of the partial agonist [N-benzylTyr(1)]Dyn A-(1-11). Modifications in the C-terminal domain of [N-benzylTyr(1)]Dyn A-(1-11)NH(2) resulted in increased kappa opioid receptor (KOR) affinity for all of the linear analogues but did not affect the efficacy of these peptides at KOR. Cyclization between positions 5 and 8 yielded [N-benzylTyr(1),cyclo(d-Asp(5),Dap(8))]Dyn A-(1-11)NH(2) (zyklophin, 13) ( J. Med. Chem. 2005 , 48 , 4500 - 4503 ) with high selectivity for KOR. In contrast to the linear peptides, this peptide exhibits negligible efficacy in the adenylyl cyclase (AC) assay and is a KOR antagonist. These data are consistent with our hypothesis that appropriate modifications in the "address" domain of Dyn A analogues may affect efficacy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Animals
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Dynorphins / chemical synthesis*
  • Dynorphins / chemistry
  • Dynorphins / pharmacology
  • Ligands
  • Mice
  • Oligopeptides / chemical synthesis*
  • Oligopeptides / chemistry
  • Oligopeptides / pharmacology
  • Peptide Fragments / chemical synthesis*
  • Peptide Fragments / chemistry
  • Peptide Fragments / pharmacology
  • Peptides, Cyclic / chemical synthesis*
  • Peptides, Cyclic / chemistry
  • Peptides, Cyclic / pharmacology
  • Radioligand Assay
  • Rats
  • Receptors, Opioid, delta / agonists
  • Receptors, Opioid, kappa / agonists*
  • Receptors, Opioid, kappa / antagonists & inhibitors
  • Receptors, Opioid, mu / agonists
  • Structure-Activity Relationship

Substances

  • Ligands
  • Oligopeptides
  • Peptide Fragments
  • Peptides, Cyclic
  • Receptors, Opioid, delta
  • Receptors, Opioid, kappa
  • Receptors, Opioid, mu
  • dynorphin A-(1-11)-NH2, Nalpha-benzylTyr(1)-cyclo(Asp(5)-Dap(8))-
  • Dynorphins
  • Adenylyl Cyclases