Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/40010
Title: Urotensin-II Peptidomimetic Incorporating a Non-Reducible 1,5-Triazole Disulfide Bond Reveals a Pseudo-Irreversible Covalent Binding Mechanism to the Urotensin G-Protein Coupled Receptor
Authors: Pacifico, Salvatore
Kerckhoffs, Aidan
Fallow, Andrew J.
Foreman, Rachel E.
Guerrini, Remo
McDonald, John
Lambert, David G
Jamieson, Andrew G.
First Published: 12-May-2017
Publisher: Royal Society of Chemistry
Citation: Organic & Biomolecular Chemistry, 2017, 15, PP. 4704-4710
Abstract: The urotensin-II receptor (UTR) is a class A GPCR that predominantly binds to the pleiotropic cyclic peptide urotensin-II (U-II). U-II is constrained by a disulfide bridge that induces a β-turn structure and binds pseudo-irreversibly to UTR and is believed to result in a structural rearrangement of the receptor. However, it is not well understood how U-II binds pseudo-irreversibly and the nature of the reorganization of the receptor that results in G-protein activation. Here we describe a series of U-II peptidomimetics incorporating a non-reducible disulfide bond structural surrogate to investigate the feasibility that native U-II binds to the G protein-coupled receptor through disulfide bond shuffling as a mechanism of covalent interaction. Disubstituted 1,2,3-triazoles were designed with the aid of computational modeling as a non-reducible mimic of the disulfide bridge (Cys5–Cys10) in U-II. Solid phase synthesis using CuAAC or RuAAC as the key macrocyclisation step provided four analogues of U-II(4–11) incorporating either a 1,5-triazole bridge (5, 6) or 1,4-triazole bridge (9, 10). Biological evaluation of compounds 5, 6, 9 and 10 was achieved using in vitro [125I]UII binding and [Ca2+]i assays at recombinant human UTR. Compounds 5 and 6 demonstrated high affinity (KD ∼ 10 nM) for the UTR and were also shown to bind reversibly as predicted and activate the UTR to increase [Ca2+]i. Importantly, our results provide new insight into the mechanism of covalent binding of U-II with the UTR.
DOI Link: 10.1039/C7OB00959C
ISSN: 1477-0520
eISSN: 1477-0539
Links: http://pubs.rsc.org/en/Content/ArticleLanding/2017/OB/C7OB00959C#!divAbstract
http://hdl.handle.net/2381/40010
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © the authors, 2017. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Appears in Collections:Published Articles, Dept. of Cardiovascular Sciences

Files in This Item:
File Description SizeFormat 
c7ob00959c.pdfPublished (publisher PDF)1.23 MBAdobe PDFView/Open


Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.