Journal Article

FZJ-2013-05905

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Identification of key residues involved in adrenomedullin binding to the AM 1 receptor

Watkins, H. ; Au, M. ; Bobby, R. ; Archbold, J. ; Abdul-Manan, N. ; Moore, J. ; Middleditch, M. ; Williams, G. ; Brimble, M. ; Dingley, A.FZJ* ; Hay, D. (Corresponding author)

2013
Wiley Malden, MA

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Please use a persistent id in citations: http://hdl.handle.net/2128/5643  doi:10.1111/bph.12118

Abstract: BACKGROUND AND PURPOSE:Adrenomedullin (AM) is a peptide hormone whose receptors are members of the class B GPCR family. They comprise a heteromer between the GPCR, the calcitonin receptor-like receptor and one of the receptor activity-modifying proteins 1-3. AM plays a significant role in angiogenesis and its antagonist fragment AM22-52 can inhibit blood vessel and tumour growth. The mechanism by which AM interacts with its receptors is unknown.EXPERIMENTAL APPROACH:We determined the AM22-52 binding epitope for the AM1 receptor extracellular domain using biophysical techniques, heteronuclear magnetic resonance spectroscopy and alanine scanning.KEY RESULTS:Chemical shift perturbation experiments located the main binding epitope for AM22-52 at the AM1 receptor to the C-terminal 8 amino acids. Isothermal titration calorimetry of AM22-52 alanine-substituted peptides indicated that Y52, G51 and I47 are essential for AM1 receptor binding and that K46 and P49 and R44 have a smaller role to play. Characterization of these peptides at the full-length AM receptors was assessed in Cos7 cells by cAMP assay. This confirmed the essential role of Y52, G51 and I47 in binding to the AM1 receptor, with their substitution resulting in ≥100-fold reduction in antagonist potency compared with AM22-52 . R44A, K46A, S48A and P49A AM22-52 decreased antagonist potency by approximately 10-fold.CONCLUSIONS AND IMPLICATIONS:This study localizes the main binding epitope of AM22-52 to its C-terminal amino acids and distinguishes essential residues involved in this binding. This will inform the development of improved AM receptor antagonists.

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Contributing Institute(s):

1. Strukturbiochemie (ICS-6)

Research Program(s):

1. 452 - Structural Biology (POF2-452) (POF2-452)

Appears in the scientific report 2013

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Database coverage:
; ; BIOSIS Previews ; Current Contents - Life Sciences ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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