Fluorescence imaging of the interaction of amyloid beta 40 peptides with live cells and model membrane

Amyloid beta peptides (A beta) found in plaques in the brain have been widely recognised as a hallmark of Alzheimer's disease although the underlying mechanism is still unknown. A beta 40 and A beta 40(A2T) peptides were synthesized and their effects on neuronal cells are reported together with the effect of tetramer forms of the peptides. ThT assay revealed that mutation affected the lag time and aggregation and the presence of lipid vesicles changed the fibril formation profile for both peptides. The A2T mutation appeared to reduce cytotoxicity and lessen binding of A beta 40 peptides to neuronal cells. Fluorescence microscopy of the interaction between A beta 40 peptides and giant unilamellar vesicles revealed that both peptides led to formation of smaller vesicles although the tetramer of A beta(A2T) appeared to promote vesicle aggregation. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.