Abstract

Acetylcholinesterase (AChE) is the enzyme responsible for the hydrolysis of the neurotransmitter acetylcholine in the central nervous system. Recently, we have found that AChE promotes the assembly of amyloid-beta peptides (A beta) into Alzheimer fibrils. The action of AChE on the state of aggregation of the A beta peptide supposes a near neighbor relationship between these two molecules. In the present work, we have studied A beta-AChE interactions using the crosslinker reagent disuccinimidyl suberate (DSS), in the presence of [I-125]-A beta peptide The A beta-AChE complexes formed by crosslinking were then analyzed by SDS-PAGE and autoradiography. We observed the formation of [I-125] A beta-labeled complexes of 70, 160, 250, and 300 kDa corresponding to monomers, dimers, tetramers, and oligomers of AChE, respectively crosslinked with the A beta peptide. Our results suggest that AChE and the A beta peptide may be involved in physiologically relevant interactions, related to the pathogenesis of Alzheimer disease (AD).