Please use this identifier to cite or link to this item:
|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|
Fallow, Andrew J.
Foreman, Rachel E.
Lambert, David G
Jamieson, Andrew G.
|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.|
|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:
|c7ob00959c.pdf||Published (publisher PDF)||1.23 MB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.