Compact fibril-like structure of amyloid β-peptide (1-42) monomers

Amyloid beta (A beta) monomers are the smallest assembly units, and play an important role in most of the individual processes involved in amyloid fibril formation. An important question is whether the monomer can adopt transient fibril-like conformations in solution. Here we use enhanced sampling simulations to study the A beta 42 monomer structural flexibility. We show that the monomer frequently adopts conformations with the N-terminus region structured very similarly to the conformation it adopts inside the fibril. This intrinsic propensity of monomeric A beta to adopt fibril-like conformations could explain the low free energy barrier for A beta 42 fibril elongation.

Automated summary

The study indicates that the Aβ42 monomer tends to adopt conformations similar to those found inside the fibril, which may explain the low free energy barrier for Aβ42 fibril elongation.