Effect of liposome membranes on disaggregation of amyloid β fibrils by dopamine

The inhibition of fibril formation of amyloid β (Aβ) and the disaggregation of Aβ fibrils are the promising approaches for a medical treatment of Alzheimer's disease (AD) therapy. In this study, we investigated the effects of liposomes on dopamine-induced disaggregation of Aβ fibrils by using the variety of liposomes. The used liposomes were normal liposomes, raft-forming liposomes, charged liposomes and oxidized liposomes. Those liposome could accelerate the disaggregation rate of fibrils. From the comparison of normal and charged liposomes, a certain contribution of dopamine via an electrostatic interaction to the disaggregation was confirmed. From raft-forming and oxidized liposomes, we revealed a significant contribution of bound water to liposomes, which could assist the formation of the quinine-form of dopamine by a removal of its proton. It is, therefore, concluded that the membrane surface of liposomes is considered to be an adequate environment for the dopamine-induced disaggregation of fibrils.