Binding modes of noncompetitive GABA-channel blockers revisited using engineered affinity-labeling reactions combined with new docking studies.
The binding modes of noncompetitive GABA(A)-channel blockers were re-examined taking into account the recent description of the 3D structure of prokaryotic pentameric ligand-gated ion channels, which provided access to new mammalian or insect GABA receptor models, emphasizing their transmembrane portion. Two putative binding modes were deciphered for this class of compounds, including the insecticide fipronil, located nearby either the intra- or the extracellular part of the membrane, respectively. These results are in full agreement with previously described affinity-labeling reactions performed with GABA(A) noncompetitive blockers (Perret et al. J. Biol. Chem.1999, 274, 25350-25354).
Charon
Sébastien
S
Laboratoire de Chimie Bioorganique, CNRS-UMR 7199, Faculté de Pharmacie, Université de Strasbourg, Strasbourg, France.
Taly
Antoine
A
Rodrigo
Jordi
J
Perret
Philippe
P
Goeldner
Maurice
M
D000345:Affinity Labels; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D058787:GABA-A Receptor Antagonists / Q000737:chemistry / Q000378:metabolism*; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D015202:Protein Engineering; D011720:Pyrazoles / Q000378:metabolism; D051381:Rats; D011963:Receptors, GABA-A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D000345:Affinity Labels; D058787:GABA-A Receptor Antagonists; D007306:Insecticides; D011720:Pyrazoles; D011963:Receptors, GABA-A; C082360:fipronil