Publication Date:
2011-01-21
Description:
General anaesthetics have enjoyed long and widespread use but their molecular mechanism of action remains poorly understood. There is good evidence that their principal targets are pentameric ligand-gated ion channels (pLGICs) such as inhibitory GABA(A) (gamma-aminobutyric acid) receptors and excitatory nicotinic acetylcholine receptors, which are respectively potentiated and inhibited by general anaesthetics. The bacterial homologue from Gloeobacter violaceus (GLIC), whose X-ray structure was recently solved, is also sensitive to clinical concentrations of general anaesthetics. Here we describe the crystal structures of the complexes propofol/GLIC and desflurane/GLIC. These reveal a common general-anaesthetic binding site, which pre-exists in the apo-structure in the upper part of the transmembrane domain of each protomer. Both molecules establish van der Waals interactions with the protein; propofol binds at the entrance of the cavity whereas the smaller, more flexible, desflurane binds deeper inside. Mutations of some amino acids lining the binding site profoundly alter the ionic response of GLIC to protons, and affect its general-anaesthetic pharmacology. Molecular dynamics simulations, performed on the wild type (WT) and two GLIC mutants, highlight differences in mobility of propofol in its binding site and help to explain these effects. These data provide a novel structural framework for the design of general anaesthetics and of allosteric modulators of brain pLGICs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nury, Hugues -- Van Renterghem, Catherine -- Weng, Yun -- Tran, Alphonso -- Baaden, Marc -- Dufresne, Virginie -- Changeux, Jean-Pierre -- Sonner, James M -- Delarue, Marc -- Corringer, Pierre-Jean -- R01 GM069379/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 Jan 20;469(7330):428-31. doi: 10.1038/nature09647.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut Pasteur, Groupe Recepteurs-Canaux, F-75015 Paris, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21248852" target="_blank"〉PubMed〈/a〉
Keywords:
Anesthetics, General/*chemistry/*metabolism
;
Binding Sites/genetics
;
Crystallography, X-Ray
;
Cyanobacteria/*chemistry
;
Electrophysiological Phenomena
;
Isoflurane/*analogs & derivatives/chemistry/metabolism
;
Ligand-Gated Ion Channels/*chemistry/genetics/*metabolism
;
Ligands
;
Models, Molecular
;
Molecular Dynamics Simulation
;
Mutant Proteins/chemistry/genetics/metabolism
;
Propofol/*chemistry/metabolism
;
Protein Binding
;
Protein Structure, Tertiary
;
Protons
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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