Probing into the interaction of β-amyloid peptides with bilayer lipid membrane by electrochemical techniques

Abstract

Alzheimer's disease (AD) is the most common degenerative disease in the elderly that is a severe threat to human health. In this paper, we report a simple but efficient electrochemical method to probe into the interaction between β-amyloid peptides and bilayer lipid membrane for revealing the toxic mechanism of AD. For this study, a supported bilayer lipid membrane is firstly modified on an electrode surface as the mimic of cell membrane, which can induce significant steric hindrance to prohibit the electrochemical probe [Fe(CN)6]3−/4− approaching the electrode. However, after incubation of the modified electrode with Aβ peptides, a noticeable electrochemical response of [Fe(CN)6]3−/4− can be obtained on the lipid membrane modified electrode, indicating the formation of ion channels in the lipid membrane. Further experimental results show that the peak current of [Fe(CN)6]3−/4− increases along with Aβ peptides concentration and incubation time. Meanwhile, the electrochemical response can be inhibited by (−)-epigallocatechin gallate, an inhibitor of the aggregation of Aβ peptides. Therefore, electrochemical technique might provide a convenient and powerful approach for in vitro studies of protein-misfolding diseases.