Preparation and photo-induced activities of water-soluble amyloid beta-C-60 complexes

Abstract

We have shown that fullerene (C-60) becomes soluble in water by mixing fullerene and amyloid beta peptide (A beta(40)) whose fibril structures are considered to be associated with Alzheimer's disease. The water-solubility of fullerene arises from the generation of a nanosized complex between fullerene and the monomer species of A beta(40) (A beta(40)-C-60). The prepared A beta(40)-C-60 exhibits photo-induced activity with visible light to induce the inhibition of A beta(40) fibrillation and the cytotoxicity for cultured HeLa cells. The observed photo-induced phenomena result from the generation of singlet oxygen via photoexcitation, inducing oxidative damage to A beta(40) and HeLa cells. The oxidized A beta(40) following photoexcitation of A beta(40)-C-60 was confirmed by mass spectrometry.