Copper abolishes the β-sheet secondary structure of preformed amyloid fibrils of amyloid-β42

摘要: The observation of the co-deposition metals and amyloid-beta(42) (A beta(42)) in brain tissue Alzheimer's disease prompted myriad investigations into role played by precipitation this peptide. Copper is bound monomeric A beta(42) upon copper-peptide complex thereby prevents from adopting a beta-sheet secondary structure. also conformers beta(42), herein we have investigated how interaction affects conformation precipitated significantly reduced thioflavin T fluorescence aged, fibrillar with, for example, 20-fold excess metal resulting ca 90% reduction fluorescence. Transmission electron microscopy showed that copper quantities amyloid fibrils while Congo red staining polarized light demonstrated copper-induced abolition apple-green birefringence. Microscopy under cross-polarized revealed first spherulites beta(42). size appearance these structures were found to be very similar identified tissue. combined results complementary methods strongly suggested abolished structure pre-formed, aged may protect against presence beta-sheets vivo, its binding could implications therapy.