Non-peptidic antagonists of the CGRP receptor, BIBN4096BS and MK-0974, interact with the calcitonin receptor-like receptor via methionine-42 and RAMP1 via tryptophan-74

Abstract

The receptor for calcitonin gene-related peptide (CGRP) has been the target for the development of novel small molecule antagonists for the treatment of migraine. Two such antagonists, BIBN4096BS and MK-0974, have shown great promise in clinical trials and hence a deeper understanding of the mechanism of their interaction with the receptor is now required. The structure of the CGRP receptor is unusual since it is comprised of a hetero-oligomeric complex between the calcitonin receptor-like receptor (CRL) and an accessory protein (RAMP1). Both the CLR and RAMP1 components have extracellular domains which interact with each other and together form part of the peptide-binding site. It seems likely that the antagonist binding site will also be located on the extracellular domains and indeed Trp-74 of RAMP1 has been shown to form part of the binding site for BIBN4096BS. However, despite a chimeric study demonstrating the role of the N-terminal domain of CLR in antagonist binding, no specific residues have been identified. Here we carry out a mutagenic screen of the extreme N-terminal domain of CLR (residues 23-63) and identify a mutant, Met-42-Ala, which displays 48-fold lower affinity for BIBN4096BS and almost 900-fold lower affinity for MK-0974. In addition, we confirm that the Trp-74-Lys mutation at human RAMP1 reduces BIBN4096BS affinity by over 300-fold and show for the first time a similar effect for MK-0974 affinity. The data suggest that the non-peptide antagonists occupy a binding site close to the interface of the N-terminal domains of CLR and RAMP1.

Publication DOI: https://doi.org/10.1016/j.bbrc.2009.11.076
Divisions: College of Health & Life Sciences > Aston Pharmacy School
College of Health & Life Sciences
College of Health & Life Sciences > Chronic and Communicable Conditions
College of Health & Life Sciences > School of Biosciences > Cellular and Molecular Biomedicine
Additional Information: Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0)
Uncontrolled Keywords: azepines,calcitonin receptor-like protein,humans,imidazoles,intracellular signaling peptides and proteins,membrane proteins,methionine,piperazines,tertiary protein structure,quinazolines,receptor activity-modifying protein 1,receptor activity-modifying proteins,calcitonin receptors,calcitonin gene-related peptide receptors,tryptophan,Biochemistry,Biophysics,Cell Biology,Molecular Biology
Publication ISSN: 1090-2104
Last Modified: 30 Sep 2024 10:01
Date Deposited: 01 May 2013 10:57
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2010-01-01
Published Online Date: 2009-11-13
Authors: Miller, Philip S.
Barwell, James
Poyner, David R. (ORCID Profile 0000-0003-1590-112X)
Wigglesworth, Mark J.
Garland, Stephen L.
Donnelly, Dan

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