Inhibition of amyloid-β protein fibrillization upon interaction with polyoxometalates nanoclusters

In this paper, two representative polyoxometalates (POMs), the wheel-shaped Preyssler anion [NaP5W30O110]14− (P5W30) and the Keggin-type anion [H2W12O40]6− (H2W12) are shown to interact with Aβ1-40 and to inhibit its fibrillization. Circular Dichroism (CD) shows that addition of both POMs dramatically altered the evolution towards the final β-sheet secondary structure. Atomic force microscopy (AFM) imaging and dynamic light scattering (DLS) experiments converge to indicate very different shapes and dimensions for the complexes formed in the absence and in the presence of the POMs. Finally, isothermal titration calorimetry (ITC) showed that both POMs showed a purely exothermic (ΔH < 0) interaction process.