Fig. 6: Schematic model for interaction of apoE with the Aβ42 fibrils.

Top panel shows apoE binds to the growing ends of the fibrillar seeds in an isoform-dependent manner with apoE3 and apoE2 binding with higher affinity than apoE4 \(({apoE}3 \sim {apoE}2 > {apoE}4)\). Binding of ApoE inhibits binding of the Aβ42 monomers to the fibril ends slowing down elongation of the fibrils, denoted by the broken arrow. Secondary nucleation is unaffected in presence of apoE. Bottom panel shows that in absence of apoE, Aβ42 fibrils can grow unhindered.