Effect of the Interaction of the Amyloid fi (1-42) Peptide with Short Single-Stranded Synthetic Nucleotide Sequences: Morphological Characterization of the Inhibition of Fibrils Formation and Fibrils Disassembly

摘要

The formation of extracellular neuritic plaques in the brain of individuals who suffered from Alzheimer's disease (AD) is a major pathological hallmark. These plaques consist of filamentous aggregates of the amyloid beta (1—42) (Aβ_(42)) proteins. Prevention or reduction of the formation of these fibrils is foreseen as a potential therapeutic approach. In this context, we investigated the interactions between the Aβ_(42) protein and polyions, in particular short single stranded synthetic nucleotide sequences. The experimental outcomes reported herein provide evidence of the inhibition of amyloid fibril genesis as well as disassembly of existing fibers through electrostatic interaction between the Aβ_(42) protein and the polyions. Since the polyions and the Aβ_(42) protein are oppositely charged, the formation of (micellar) inter polyelectrolyte complexes (IPECs) is likely to occur. Since the abnormal deposition of amyloid fibers is an archetype of AD, the outcomes of these investigations, supported by atomic force microscopy imaging in the dry and liquid states, as well as circular dichroism and Fourier transform infrared spectroscopy, are of high interest for the development of future strategies to cure a disease that concerns an ever aging population.