Zinc ion (Zn2+) (Zn2+)

Zinc ions (Zn2+) are critical inorganic components that modulate the aggregation and toxicity of amyloid-beta (Aβ) peptides in Alzheimer's disease. Under physiological conditions, zinc is released from glutamatergic synapses and is essential for synaptic plasticity and memory formation (NIH, 2023). However, in the Alzheimer's brain, Zn2+ binds to the N-terminal histidine residues of Aβ, acting as a cross-linking agent that triggers the formation of insoluble plaques and neurotoxic oligomers (PubMed, PMID: 8128245). This sequestration of zinc into plaques creates a "zinc dyshomeostasis" where synaptic levels are depleted while extracellular deposits increase. Pharmacological strategies, such as Metal Protein Attenuating Compounds (MPACs), aim to disrupt these Aβ-Zn complexes to promote plaque dissolution and restore normal metal distribution (Adlard et al., 2008). Notable drug candidates like PBT2 have been investigated for their ability to act as ionophores, moving zinc from the extracellular space back into neurons to support cognitive function. Despite the potential, therapeutic development faces challenges in achieving high selectivity for Aβ-bound zinc to avoid systemic toxicity or interference with essential zinc-dependent enzymes.

Other names

Zinc(II)Zn(2+)Divalent zincAmyloid-beta-associated zincSynaptic zinc

Metal protein attenuating compounds (MPACs) or chelators disrupt the binding of zinc to amyloid-beta peptides, thereby inhibiting aggregation and promoting the clearance of existing plaques.