Studies on the interactions of copper and zinc ions with β-amyloid peptides by a surface plasmon resonance biosensor

Abstract

The aggregation of β-amyloid peptide (Aβ) into fibrils plays an important role in the pathogenesis of Alzheimer's disease (AD). Metal ions including copper and zinc are closely connected to the precipitation and toxicity of Aβ. In this study, a surface plasmon resonance (SPR) biosensor was constructed to investigate the interactions between Aβ and metal ions. Aβ peptide was immobilized on the SPR chip surface through a preformed alkanethiol self-assembled monolayer (SAM). Our observations indicate that the immobilized Aβ undergoes a conformational change upon exposure to the metal ions. A difference in metal binding affinity between Aβ1-28 and Aβ1-42 was also detected. The results suggest that SPR is an effective method to characterize the interactions between Aβ and metal ions. © 2012 by the authors; licensee MDPI, Basel, Switzerland.