The necessity of having a tetradentate ligand to extract copper(II) ions from amyloids

Michel Nguyen (1) , Lionel Rechignat (1) , Anne Robert (1) , B. Meunier (1, 2)

1 LCC - Laboratoire de chimie de coordination
2 GUST - Guangdong University of Science and Technology

The accumulation of redox-active metal ions, in particular copper, in amyloid plaques is considered to the cause of the intensive oxidation damage to the brain of patients with Alzheimers disease (AD). Drug candidates based on a bis(8-aminoquinoline) tetradentate ligand are able to efficiently extract Cu2+ from copper-loaded amyloids (Cu–Aβ). Contrarily, in the presence of a bidentate hydroxyquinoline, such as clioquinol, the copper is not released from Aβ, but remains sequestrated within a Aβ–Cu–clioquinol ternary complex that has been characterized by mass spectrometry. Facile extraction of copper(II) at a low amyloid/ligand ratio is essential for the re-introduction of copper in regular metal circulation in the brain. As, upon reduction, the Cu+ is easily released from the bis(8-aminoquinoline) ligand unable to accommodate CuI, it should be taken by proteins with an affinity for copper. So, the tetradentate bis(8-aminoquinoline) described here might act as a regulator of copper homeostasis.

Domaines: Chimie de coordination

Michel Nguyen, Lionel Rechignat, Anne Robert, B. Meunier. The necessity of having a tetradentate ligand to extract copper(II) ions from amyloids. ChemistryOpen, 2015, 4 (1), pp.27-31. ⟨10.1002/open.201402075⟩. ⟨hal-01920330⟩