Journal of Thermodynamics & Catalysis
Open Access

Abstract

Molecular Interactions between Ligands and Nicotinic Acetylcholine Receptors Revealed by Studies with Acetylcholine Binding Proteins

Hugo R. Arias

Nicotinic acetylcholine receptors (AChRs) are the best characterized ion channels representing the Cys-loop ligand-gated ion channel superfamily. Studies using Torpedo AChRs in the closed and open states andacetylcholine binding proteins (AChBPs) from different origins have elucidated the most important structural and functional features of the agonist/competitive antagonistbinding sites. The first step in recognizing the neurotransmitter ACh and other agonists is fundamental in the process of agonist-induced activation, including the opening of the intrinsic cation channel. The AChBP studies demonstrated that Loop C is an important structural feature that is modified by ligand binding. These studies defined important pharmacologic features of AChR ligands, including the differences between full and partial agonists, agonists and competitive antagonists, peptidic and non-peptidic ligands, and between high affinity and high selectivity. The studies showing the structural mechanisms by which specific ligands can activate, inhibit, and potentiate different AChR subtypes could be of therapeutic importance.