Progression of Alzheimer’s disease is accompanied by the dysfunction of the cholinergic system and massive loss of cholinergic neurons containing the nicotinic acetylcholine receptors (nAChR). NAChR agonists protect neuronal cells against amyloid toxicity, eliminate the senile plaques, and improve learning and memory of transgenic mice. Moreover, nAChRs antagonists, that block the binding of Abeta to the receptor, inhibit Abeta-induced tau protein phosphorylation in neuronal cells. It means that the toxicity of Aβ is mediated through a direct interaction between Abeta and nAChRs. The most abundant form of nAChRs in the brain is alpha4beta2 nAChR. It is known that Abeta binds alpha4beta2 nAChR and inhibits its function but little is known about this interaction. Using microscale thermophoresis and isothermal titration calorimetry, we have shown that Abeta forms a strong complex with the extracellular domain (32-242aa) of nAChR alpha4 subunit through the region 35-HAEE-38 of alpha4. Isomerization of Asp7, the well-known pathogenic modification of Abeta, enhances this interaction 10-fold. Mutation 35-HAАА-38 completely abolishes the binding of alpha4 nAChR and Abetas, as well as Abeta-induced inhibition of alpha4beta2 nAChR in Xenopus laevis oocytes measured by two-electrode voltage clamp. The initial binding of Abeta peptides to the alpha4 nAChR promotes their aggregation on the receptor matrix. Thus, the region 35-HAEE-38 of alpha4 nAChR is essential for interaction with Abeta. An increase in Abeta level induces its aggregation on the receptor and results in the inhibition of the nAChR. Supported by the Russian Science Foundation (grant #19-74-30007).