Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-1-26
pubmed:abstractText
Benzodiazepines are used for their sedative/hypnotic, anxiolytic, muscle relaxant, and anticonvulsive effects. They exert their actions through a specific high affinity binding site on the major inhibitory neurotransmitter receptor, the gamma-aminobutyric acid, type A (GABA(A)) receptor channel, where they act as positive allosteric modulators. To start to elucidate the relative positioning of benzodiazepine binding site ligands in their binding pocket, GABA(A) receptor residues thought to reside in the site were individually mutated to cysteine and combined with benzodiazepine analogs carrying substituents reactive to cysteine. Direct apposition of such reactive partners is expected to lead to an irreversible site-directed reaction. We describe here the covalent interaction of alpha(1)H101C with a reactive group attached to the C-7 position of diazepam. This interaction was studied at the level of radioactive ligand binding and at the functional level using electrophysiological methods. Covalent reaction occurs concomitantly with occupancy of the binding pocket. It stabilizes the receptor in its allosterically stimulated conformation. Covalent modification is not observed in wild type receptors or when using mutated alpha(1)H101C-containing receptors in combination with the reactive ligand pre-reacted with a sulfhydryl group, and the modification rate is reduced by the binding site ligand Ro15-1788. We present in addition evidence that gamma(2)Ala-79 is probably located in the access pathway of the ligand to its binding pocket.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3160-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:14612433-Allosteric Site, pubmed-meshheading:14612433-Animals, pubmed-meshheading:14612433-Benzodiazepines, pubmed-meshheading:14612433-Binding Sites, pubmed-meshheading:14612433-Cell Line, pubmed-meshheading:14612433-Cell Membrane, pubmed-meshheading:14612433-Cysteine, pubmed-meshheading:14612433-Dose-Response Relationship, Drug, pubmed-meshheading:14612433-Electrophysiology, pubmed-meshheading:14612433-Flunitrazepam, pubmed-meshheading:14612433-GABA Modulators, pubmed-meshheading:14612433-Humans, pubmed-meshheading:14612433-Kinetics, pubmed-meshheading:14612433-Ligands, pubmed-meshheading:14612433-Models, Chemical, pubmed-meshheading:14612433-Mutagenesis, Site-Directed, pubmed-meshheading:14612433-Mutation, pubmed-meshheading:14612433-Oocytes, pubmed-meshheading:14612433-Patch-Clamp Techniques, pubmed-meshheading:14612433-Protein Binding, pubmed-meshheading:14612433-Protein Conformation, pubmed-meshheading:14612433-RNA, Complementary, pubmed-meshheading:14612433-Rats, pubmed-meshheading:14612433-Receptors, GABA-A, pubmed-meshheading:14612433-Time Factors, pubmed-meshheading:14612433-Transfection, pubmed-meshheading:14612433-Xenopus
pubmed:year
2004
pubmed:articleTitle
On the benzodiazepine binding pocket in GABAA receptors.
pubmed:affiliation
Department of Pharmacology, University of Bern, CH-3010 Bern, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't