[2P37] Effect of non-equilibrium space on initial aggregation of amyloid β at lipid membrane interface
Alzheimer’s disease (AD) is a difficult-to-treat disease in which amyloid β (Aβ) aggregates and accumulates on the surface of the brain cells. The molecular mechanism is partially unclear, as the interstitial fluid keeps the brain in a non-equilibrium condition by supplying and removing substances, which complicates the aggregation and accumulation processes. However, since previous studies have examined the equilibrium close space, we have carried out the single molecule observation of Aβ on the lipid membrane in a non-equilibrium open space, especially focusing on the formation of Aβ oligomer that is most cytotoxic to the membrane. The oligomer size of Aβ was quantified by identifying the Aβ monomer from a photobleaching behavior. In the non-equilibrium open space, the amount of monomer adsorbed on the membrane surface was maintained even as the oligomerization proceeds, which promoted the Aβ aggregation at a molecular level. In conclusion, we propose initial aggregation process that the amount of adsorption and aggregation of Aβ reach non-equilibrium steady state under open space.