Abstract

Amyloid b-peptide (Ab) is a natural peptide of about 39-42 amino acids, which can aggregate and accumulate into senile plaques, one of the main pathological features in Alzheimer's disease (AD).There is extensive evidence that neurodegenerative pathologies, such as AD, are associated with protein misfolding and environmental factors, such as heavy metals, that are known to pollute the environment and can be taken up by the organism in food. They can accumulate within organs and tissues, with sometimes dramatic effects. There is increasing evidence that heavy metals can interact with amyloid b peptides, contributing to the neurodegenerative events of AD. We investigated the effects of Cd⁺⁺, an environmental contaminant on AbP1-42 aggregation, incorporation and channel formation into planar lipid membranes made up of phosphatidylcholine: cholesterol (70:30, w/w). Our results suggest that Cd⁺⁺ interferes both with channels already incorporated into membranes and with peptides in solution. These findings provide important clues to the effect of this environmental contaminant on AbP1-42 that similarly to other metal ions, such as copper, zinc, aluminium and iron, can lead to abnormal interactions with proteins, contributing to cell damage.

Key words: Amyloid b-peptide (AbP) 1-42, cadmium, planar lipid membrane, ion channel.