Related Experiment Video
Updated: Aug 14, 2026

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
Conformational analysis of kainate in aqueous solution in relation to its binding to AMPA and kainic acid receptors
1Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Copenhagen.
Abstract:
Conformational analyses for kainate in aqueous solution have been performed by using the MM3*, AMBER* and MMFF94 force fields in conjunction with the Generalized Born Solvent Accessible Surface (GB/SA) hydration model. A comparison of calculated results with experimentally determined conformational data indicates that MM3*-GB/SA strongly overestimates the stability of a hydrogen bonded ion-pair in aqueous solution in comparison with the separated and solvated ions. This results in an incorrect prediction by MM3* of the most stable conformer of kainate in aqueous solution, whereas AMBER* and MMFF94 correctly predict the lowest energy conformer. Calculated conformational energy penalties for binding of kainate to the AMPA iGluR2 receptor indicate that the lower affinity of kainate for AMPA receptors compared to its affinity for kainic acid (KA) receptors is not due to a higher energy bioactive conformation of kainate at AMPA receptors. This conclusion is strongly supported by an analysis of a recently reported nonselective AMPA/KA ligand and a comparison of the conformational and structural properties of this ligand with iGluR2-bound kainate. This comparison strongly suggests that kainate binds to AMPA and KA receptors in closely the same conformation.
Related Concept Videos
Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Ligand-gated Ion Channels
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Basicity of Aliphatic Amines
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Quantitative Aspects of Drug-Receptor Interaction
Extraction: Effects of pH

