| Anion regulation of [3H]strychnine binding to glycine-gated chloride channels is explained by the presence of two anion binding sites. | |
| | |
MedLine Citation:
|
PMID: 2849048 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The effects of six monovalent anions (chloride, bromide, iodide, nitrate, perchlorate, and thiocyanate) on [3H]strychnine binding to glycine-gated chloride channels were examined. These anions have previously been shown to permeate glycine-gated chloride channels and stimulate [3H]strychnine binding. Whereas low concentrations (10-200 mM) of all these anions enhanced [3H]strychnine binding, higher concentrations (0.2-3 M) of thiocyanate, perchlorate, and iodide produced a robust inhibition of radioligand binding, and a more modest inhibition was observed with the same concentrations of nitrate and bromide. The presence of one binding site for anions at glycine-gated chloride channels can account for either the activation or the inhibition phase, but not both. However, these biphasic effects can be explained by the presence of two binding sites for anions at these channels. Two models with two anion binding sites were considered, the first assuming both allosteric activation and inhibition of the binding of the ligand, and the other explained by allosteric activation combined with competitive inhibition. Mathematical expressions for both models were formulated, and the equations obtained yielded satisfactory fitting to the results obtained with all anions tested in both concentration-response and saturation experiments. These equations also permitted the calculation of several parameters describing the interaction of the anions with these channels. The main difference in the behavior of these anions relates to the extent to which they produce activation of [3H]strychnine binding and to their cooperative interaction at the two putative anion binding sites. Thus, a strong negative cooperativity was observed for the simultaneous binding of two molecules of chloride, bromide, or nitrate, but not for the simultaneous binding of thiocyanate, perchlorate, or iodide. This latter property may be related to the conductance of these anions through glycine-gated chloride channels. |
| | |
Authors:
|
J C Marvizón; P Skolnick |
Related Documents
:
|
12713318 - Calix[4]arenes containing ferrocene amide as carboxylate anion receptors and sensors. 21176908 - Performance of hexamer peptide ligands for affinity purification of immunoglobulin g fr... 16836358 - Anion binding to monotopic and ditopic macrocyclic amides. 15188038 - Recognition of alpha-amino acid derivatives by n,n'-dibenzylated s,s-(+)-tetrandrine. 22353148 - Probing the binding of the flavonoid diosmetin to human serum albumin by multi-spectros... 11285238 - Lap2 binds to baf.dna complexes: requirement for the lem domain and modulation by varia... |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: Molecular pharmacology Volume: 34 ISSN: 0026-895X ISO Abbreviation: Mol. Pharmacol. Publication Date: 1988 Dec |
Date Detail:
|
Created Date: 1989-01-23 Completed Date: 1989-01-23 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0035623 Medline TA: Mol Pharmacol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 806-13 Citation Subset: IM |
Affiliation:
|
Laboratory of Neuroscience, National Institute of Diabetes Digestive and Kidney Diseases, Bethesda, Maryland 20892. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Allosteric Regulation Animals Anions / metabolism* Binding Sites Cell Membrane Permeability Chloride Channels Chlorides / metabolism* Glycine / physiology* Male Membrane Proteins / metabolism* Models, Biological Radioligand Assay Rats Rats, Inbred Strains Receptors, Glycine* Receptors, Neurotransmitter / metabolism Strychnine / metabolism* |
| Chemical | |
Reg. No./Substance:
|
0/Anions; 0/Chloride Channels; 0/Chlorides; 0/Membrane Proteins; 0/Receptors, Glycine; 0/Receptors, Neurotransmitter; 0/strychnine receptor; 56-40-6/Glycine; 57-24-9/Strychnine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Characterization of porphyrin interactions with peripheral type benzodiazepine receptors.
Next Document: Delta 9-tetrahydrocannabinol increases arachidonic acid levels in guinea pig cerebral cortex slices.