The role of magnetic iron nanoparticles in recombinant human Tau protein fibrillization

Accumulations of biogenic magnetite (Fe3O4) in the brain and dysregulation of iron transport and storage have been found to be associated with many neurodegenerative disorders, such as Alzheimer disease. AD is a progressive neurodegenerative disorder that causes disruptions in memory and cognition. Several studies have shown that pathogenesis of AD is also related to protein misfolding and aggregation of tau protein in the brain. Microtubule-associated tau protein belongs to a family of intrinsically disordered proteins that promotes microtubule assembly and stability. In the present study, we investigated the interaction between recombinant human tau and magnetic iron nanoparticles by using ThT fuorescence and transmission electron microscopy. Our results showed that magnetic iron nanoparticles induced tau conformational changes from random-coil to β-sheet and consequently resulted in the formation of tau fibrils. In conclusion, our results proposes a probable mechanism for the correlation between aggregation of tau protein and biogenic magnetite crystals in AD.