Structure-activity relationships and structural conformation of a novel urotensin II-related peptide.
Urotensin II (UII) has been described as the most potent vasoconstrictor peptide and recognized as the endogenous ligand of the orphan G protein-coupled receptor GPR14. Recently, a UII-related peptide (URP) has been isolated from the rat brain and its sequence has been established as H-Ala-Cys-Phe-Trp-Lys-Tyr-Cys-Val-OH. In order to study the structure-function relationships of URP, we have synthesized a series of URP analogs and measured their binding affinity on hGPR14-transfected cells and their contractile activity in a rat aortic ring bioassay. Alanine substitution of each residue of URP significantly reduced the binding affinity and the contractile activity of the peptides, except for the Ala8-substituted analog that retained biological activity. Most importantly, D-scan of URP revealed that [D-Trp4]URP abrogated and [D-Tyr6]URP partially suppressed the UII-evoked contractile response. [Orn5]URP, which had very low agonistic efficacy, was the most potent antagonist in this series. The solution structure of URP has been determined by 1H NMR spectroscopy and molecular dynamics. URP exhibited a single conformation characterized by an inverse gamma-turn comprising residues Trp-Lys-Tyr which plays a crucial role in the biological activity of URP. These pharmacological and structural data should prove useful for the rational design of non-peptide ligands as potential GPR14 agonists and antagonists.
Chatenet
David
D
Laboratory of Cellular and Molecular Neuroendocrinology, European Institute for Peptide Research (IFRMP 23), INSERM U413, UA CNRS, University of Rouen, 76821 Mont-Saint-Aignan, France.
Dubessy
Christophe
C
Leprince
Jérôme
J
Boularan
Cédric
C
Carlier
Ludovic
L
Ségalas-Milazzo
Isabelle
I
Guilhaudis
Laure
L
Oulyadi
Hassan
H
Davoust
Daniel
D
Scalbert
Elizabeth
E
Pfeiffer
Bruno
B
Renard
Pierre
P
Tonon
Marie-Christine
MC
Lihrmann
Isabelle
I
Pacaud
Pierre
P
Vaudry
Hubert
H
D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010446:Peptide Fragments; D036361:Peptide Hormones / Q000737:chemistry*; D011487:Protein Conformation
D047908:Intracellular Signaling Peptides and Proteins; D010446:Peptide Fragments; D036361:Peptide Hormones; C479080:UTS2B protein, human; C479081:urotensin II-related peptide, rat