Spontaneous beta-barrel formation: an all-atom study of Abeta(16-22) oligomerization

Summary, in English

Using all-atom Monte Carlo simulations with implicit water, combined with a cluster size analysis, we study the aggregation of A16-22, a peptide capable of forming amyloid fibrils. We consider a system of six initially randomly oriented A16-22 peptides, and investigate the thermodynamics and structural properties of aggregates formed by this system. The system is unaggregated without ordered secondary structure at high temperature, and forms -sheet rich aggregates at low temperature. At the crossover between these two regimes, we find that clusters of all sizes occur, whereas the -strand content is low. In one of several runs, we observe the spontaneous formation of a -barrel with six antiparallel strands. The -barrel stands out as the by far most long-lived aggregate seen in our simulations.