Analysis of binding centers in nicotinic receptors with the aid of synthetic peptides

We studies the receptor-binding specificity of the synthetic peptide HAP (High Affinity Peptide) and its analogues, which are regarded as a model of the orthosteric site nicotinic acetylcholine receptors (nAChR). Using radioligand analysis, electrophysiology tests, and calcium imaging, we assessed the ability of HAP to interact with nAChR antagonists: long alpha-neurotoxins and alpha-conotoxins. A high affinity of HAP for alpha-bungarotoxin and the absence of its interaction with alpha-cobratoxin and alpha-conotoxins was found. The synthesized analogues of HAP in general retained the properties of the original peptide. Thus, HAP cannot be a model of a ligand-binding site.