Studies of interaction of copper and zinc ions with Alzheimerʹs Aβ(1–16) using surface plasmon resonance spectrometer

Amyloid β peptide plays a critical role in the pathogenesis of Alzheimerʹs disease (AD). Transition metals, such as Cu(II), Zn(II), and Fe(III) are found in Aβ plaques, and they have been shown to affect Aβ aggregation. Here we investigated the interactions between metal ions and Aβ1–16 by a flow-injection surface plasmon resonance spectrometry (SPR). Our study revealed that both Zn(II) and Cu(II) promoted human Aβ1–16 conformation change but the Zn(II)-induced conformation change is greater. However, rat Aβ1–16 binds Zn(II) less avidly and hardly any conformation change, this may due to three point substitutions, R5G, Y10F, and H13R in rat Aβ1–16 which appear to alter the physicochemical properties of the peptide.